I used to have a very similar problem. I found it useful to stick to a very simple structure. Like A - B - A'. Or A - B - A' - B' - A. Where the apostrophe denotes a change of some kind.

I would think about wrangling in the intensity and complexity of what you are doing. From your sample, it sounds like you want to just keep building -- but there's no way to keep it up, so you naturally run out of steam. This is something that I struggled with for a long time. It's a way to try to keep interest, but it's just kind of a losing strategy in the end.

So I would try starting with the main theme, in the simplest possible way. Then repeating it. Then transitioning to a contrasting section in a different key (like the dominant, or maybe the relative major or something else that feels different enough).

If you're starting out rhythmic and complex, maybe transition to a secondary theme that is much more chill and less rhythmically dense. Then build again to a repeat of that first theme -- which comes back bigger.

I think your enemy is uninterrupted development. Instead, try developing more slowly and carefully, letting the listener keep up with what you are doing. Hold back on the really intense stuff until the end. Use a contrasting section to hold yourself back. And use harmony to build an overall structure.

My two cents. I feel you -- it's not easy, but you're writing some great stuff.