Hi again,
You just got it right 
and it’s alright to feel that way. Music Production is a never ending learning curve & process and it’s often frustrating & overwhelming. This has become even more true with the Web & the huge amount of knowledge that one can now access. That said, I will come back to my previous post and the first advise would be to keep the frontier between musical creativity & audio production techniques. Of course they are linked in terms of workflow & setup in order to be able to keep your inspiration going in an easy & enjoyable way, but when it comes to mixing, track enhancement or even mastering, you have to kind of separate those 2 aspects and break down things into steps.
To illustrate the real concept behind this I will refer to those words : “The more you grow your knowledge, the more you grow your pain” and it’s really true with music production but I think that music should remain fun & enjoyable before frustrating you, so it’s really important to separate creativity & techniques.
Another point is about questions like “what audio techniques & tools do I need to learn ?”, “when & where do I need or should I place this or that audio effect in the mix ?”, “what’s the best compressor to use on that particular sound ?” and the list could never be ending because of the enormous amount of tools & techniques you can use, the advise you can read, hear & watch.
So here again, I will rely on 2 big guys in the music industry to illustrate the concept behind this:
Audio engineer Andrew Scheps did a great lecture with the subject “in the end, the only thing that matter is what comes out of the speakers” Andrew Scheps at the University of Oxford - "What Comes Out Of The Speakers". - YouTube and another great audio engineer Dave Pensado was asked by the guys at LANDR ( online music mastering platform ) to give 15 mixing tips that every producer should know 15 Dave Pensado Mix Tips Every Producer Should Start Using Now - YouTube which he did but the most important tip was N°15 where he stated that even if the previous 14 tips could be good to know, they are no best rules & best mixing practice in the end. 
So to sum it all, I think it’s important to learn audio techniques in order to have choices and to help you to setup a good workflow that works fine for you & your mix, they are just tools after all.
This could be very much different from one mix to another if you’re producing different kind/genre of music or the other way : more or less the same if you aim at one genre and a particular & personal sound signature. This has more to do with your goals in the music production world, leading to a very important new question : is it just a hobby, are you enjoying to produce for yourself or are you aiming to sound like others, or just the opposite : sounding different & unique ?
Another controversial subject that can be simplify going back to point one : keep it enjoyable on the creative side of things and trust yourself & believe that if your music is pleasing you and if you’re happy and satisfy by “what comes out of your speakers”, chances are that it will please someone else ears too 
Well… If you’re still reading this you might think that this is more a philosopher speech than a music production insider tips with the best web links & books you should absolutely read and can’t live without…
But there is simply no such perfect learning path, except if you just want to replicate other’s techniques. The goal in learning audio production techniques is to understand them, to discover new ways of doing things, sometimes not conventional to enhance your creativity and at a certain point your overall mixes quality of course.
That’s why I love Sonic Academy BTW, because you can learn in different aspects like “How to sound like”, “How to use” DAWs & Plugins, “How to make” complete tracks with different artists workflow & knowledge, “Tech & Tips series” and even “Artists Interview” which makes it a very good place to learn.
But OK, there’s anyway a few recommendations that I can’t go wrong to give and that are kind of basic do & don’t to try to find your way on the long ( endless ?? ) road of music production learning path 
- Studio Setup : both hardware & software
Your listening environment is critical and your production workflow too.
So make it reliable in terms of audio setup and also nice & comfortable.
Good Monitors, headphones, decent audio card and a DAW that you feel comfortable to work with are very important.
If you’re more into getting musical ideas & record them to DAW on the fly, you could think NI Maschine or Ableton Push or whatever other Midi based controller or synth but if you’re not, it’s not a must have, your DAW of choice & the mouse & keyboard will do the job !
- Learn you gears & inside the box plugins before wanting more & buy new stuffs. Nowadays, most of the DAW comes bundled with very good plugins and you have to learn to mix inside the box before turning to high quality plugins or analog gears. Always take the time to learn what you have and to get out the best out of plugins & gears. You should reach the need for something new or from higher end when you feel that you really need it to push your work further. It will save you money & disappointment & having too many tools to choose from can quickly become counter-productive.
Getting a new software or hardware synth is one thing because you’re aiming for a particular sound that you love or want, but turning too high end & more complicated gears & audio effects is a different thing.
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Always take the time to reference your work, and I’m not only talking about full track referencing for mixing, but take the time to A/B per track, before and after audio effects to listen if it’s really adding something to the sound or doing the opposite and degrading the track.
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Learn common practice rules but be curious and try others & new things. As an example, take the never ending question : “should I EQ before or after putting in a compressor ?” and you’ll find people relaying on only one rule that you “must” apply, but creative people would EQ before & after the compressor and even use more that one type of compressor on the same track ( going back to “what comes out of the speaker” is what matter in the end).
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Refresh you ears and mind often, music making and getting that mix to sound to your liking has to remain fun & enjoyable. If you don’t get there after too much time, make a break and try a new approach coming back to your work.
Spending too much time to get that sound could mean you’ve been wrong at an earlier stage. As an example, imagine yourself trying to make a sampler or an audio track sounding good using all the knobs you know and adding all your best effects chain and no way to get there… More than annoying & frustrating after a while, right ? And what if it’s the sample or the audio recording which was a wrong choice or a poor quality right from the start ??
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Challenge yourself in the process by setting restrictions like making a track sound decent with only a few specifics effects, only one or a few imposed samples or synths : you will push yourself to get out the most of your plugins & gears and learn a lot.
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In terms of topics it’s good to have a practical understanding of EQ , Compressors ( what type exists and how each of them works and respond : i.e VCA, FET, Tube for compressors and classic EQ vs Linear ones or dynamics ones ) but also Frequencies ranges and frequency masking/dueling, side-chain & frequency filtering and cleaning ( removing unwanted frequencies in a mix ), Mid/Side mixing/mastering vs stereo.
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Thinks about music in a 4 dimensional environment : front, back, center, sides and set your instruments & tracks to mono or stereo accordingly, make use of panning to give more live to your mix or to reduce frequency masking issues.
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Mixing at low levels on small speakers can help to get a good overall sounding mix while mixing on bigger monitors or high end headphones ( both as flat as possible ) should help to adjust fine details.
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Mixing levels and gain staging is a very important topic I think, techniques like the Bob Katz K-14 & K-18 are great subjects in regards to keep audio quality & dynamics VS the Loudness War approach.
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Mixing & Mastering chains, Limiters & Mastering EQs are important knowledge to grab too, but those chains should vary depending of your music genre and again, nothing is written in stones when it comes to music production, so it’s good to try to understand concepts about perceptive loudness and how our ears are often tricking us and how to avoid this too much before searching for the perfect & magic mastering channel chain.
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Bear in mind that music is mainly based around math, especially when it comes to the digital music world. Some people may want to get into that area of knowledge because they have the mind for it, and because numbers will help them to better understand the way effects works and how to set them up, but if you’re more focusing on the creative aspect, it’s not mandatory: trust your ears instead !!
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It can help to have a good picture of the digital world VS the analog one, especially in terms of level at which plugins and real world gears operates to get best sounding results. 0 Dbfs in the digital world matches around -18 / -21 Db on analog desk & gears, therefore high end plugins design after real gears to match them , such as the Waves or the UAD ones, should operate best at low input levels around -18/-20 Dbfs. That’ why again it’s a good practice ( in my opinion ) to mix using the -k14 or even -k18 B.Katz metering scale and to always leave your 2bus at 0Dbfs and never touch that master-fader !
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Talking about the 2bus, it can also help to Bus & Groups tracks to sub-groups all redirected to a dry Pre-master 2Bus before being send to a final Master 2Bus channel. It’s important to do gain-staging on the go while developing your mix and set appropriate level for each track and take care of some frequency masking or perform subtraction Equing to clean your sound. The goal is to have an already nice balanced & consistent mix before even thinking about any mastering stage.
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When you find a sample you like or craft a preset you’re happy with, SAVE IT ! Organize your sound & presets libraries to be reliable and easy to navigate and use instead of the deepest ocean of sounds.
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Same goes for DAW, save your work on a regular basis, make per channel or full mix templates to help you start a new musical idea faster and did I said SAVE your work ?? Software & Computers crash often and they won’t warn you.
I could go on with numerous other tips that you might find valuable or not, I’ll probably will think that I missed some important things when reading myself again and that’s it really : it’s a journey, a long road with some pure ecstasy & delightful instants but also numerous moment of doubt & disillusion.
Keep it to this point: the most important is to keep the fun and to enjoy doing it, to learn at your own pace with desire & curiosity and still joy.
The knowledge is everywhere, grab the fundamentals like you seem to have started already
To keep it to Sonic Academy here, again I think it’s a really good place to learn a ton of great & different things, you can refer to the following page to help you fine search course or even just video from courses using the filters & search fields like below All Courses
Hope I did not bother you too much with this long post…
Cheers !
Time to continue on educating myself on a lot more now!
but there’s so much to say when it comes to “where should I start ??”