i am a firm believer that the less you know about music theory the more you are creating from the heart.

Yeah I think that's a romantic notion that is not true at all.

I think it's important to accept other strategies are just as valid as yours, and not insist that they way you do it is the one true path. Setting articifical deadlines and imbuing everything with an explicit, verbal message isn't everyone else's modus operandi, and there's no reason to think less of you when it is yours.

I'd think I'd want all the layers sidechained the same.

Not necessarily. You could have a part with both high and low frequencies in it that you don't actually want to sound like it's being sidechained, but it's fighting the kick in the lows for example, so what you do is duck the parts that actually interfere and leave the rest alone.

I also start with the kick at -12dB. When I'm ready to commit to the premaster, I render a copy, see if there are any stray really bad peaks, tame those in the mix, then render out of Live with the normalize function on. That gives me the optimal balance between using as much of the precision as possible and having the track sound as intended. Usually, the kicks peak at -5 to -2 dB at this point. And then it's off to mastering, which I don't do myself But a quick maximizer pass on the premaster will usually sound okay enough to put it on soundcloud and not have it drown completely around professionally mastered tunes.

What's important is that your kick and sub bass don't occupy the same frequency, at least not without some good sidechain compression

Not at the same time, I'd say.

I usually find that you can do a lot of stuff to pads that would sound awful if they were soloed but work fine in the mix. Drastic EQ cuts and filters, volume ducking around other elements, that sort of thing.

The part before the build has a nice groove to it with the bass line and the choppy chords

There's room for some quick and easy wins here: Your kick and snare have an annoying flam (double-hit) that you can get rid of. Your kick is also a bit too slappy, check the high mids and treble there. You have some weird drop-out/panning screw-ups in the hats that I'm not sure are deliberate? Make sure there's nothing weird going on with the channel. And then the snare roll in the build-up just fizzles since it's got no foundation to stand on, and no context around it. You can give it some bottom end, add some transition effects, make the listener WANT the drop.

There are also some issues that will be considerably harder to fix: In the break, there's not enough harmonic complexity, with just the piano and a single note of strings, and a really basic progression. The melody sounds a bit disjointed and random as well; maybe check the composition forum here for advice on writing melodies! In the main part, suddenly there are too many things fighting for the same frequency room and it gets mighty busy in the mids, while the chords still sound samey and it makes the track feel harmonically empty and boring. It's really hard to give constructive advice here—I feel like that's a fundamental compositional problem that may not be fixable without a rewrite.

Overall, perhaps it's best to just do some minor polishing (really, the kick and snare double hit is the most egregious thing ), call this finished, stow it away, and move on to the next thing. That is not meant to be a harsh or unfriendly critique and I hope you don't take it that way. It's a skill worth having to know when you've hit a dead end. Finish this, then write your next thing, it'll be fine.