Improving beyond a certain point

Hello guys,

I need some inputs into how I get better beyond a certain point, as I've hit a wall; or so it seems. I'm a bit of a tryhard, with very little opportunity to join physical tournaments (because geography) and finding the time for TTS has been a real pain. Since i've started using the Tabtetop App, i've clocked in 21 games with a score of 4 wins, 16 losses. I play Tyranids, and my current list is pretty much a cookie-cutter 2 Exocrine, 2x maleceptor build with gargoyles, lictors etc. (ie. the list is def not the problem as far as i can tell)

Now, my record isn't super surprising as this includes me being fairly new at the game, and that's to be expected; and overall, I've enjoyed playing so far!

So, the question: How do you/I properly analyse my games and identify my mistakes and improve upon them? What strategies do you use, how do you plan ahead/test said improvements etc etc? And i'm referring specifically to "how to improve gameplay", as i've spent a lot of time (too much) focusing on list-building (and painting).

What's your process, how do you approach the post-game analysis, do's and don'ts? Please, hit me up and help me improve further.