Question about the midpoint

I’ve always been a pantser because I don’t do well with anything that I interpret as restrictive, but I always get lost a third of the way into a novel, and I’ve decided to experiment with different plot structures to see what amount of planning helps me. That being said, the reason I never got into the three-act, seven-point, etc. is because of how mathematical they seem, especially when they give percentages (ie. the first plot point should be around 20%, I don’t know). I really enjoy ways of plotting that aren’t linear, such as the snowflake method or the thematic square, but I still want to make sure my plot lines up somewhat with a three-act structure. (Is that silly?)

And my real issue is that my midpoint is not anywhere near where I think the middle will be. It’s much later. I realize that this differs from genre to genre, but I also disagree with the concept of the midpoint on a fundamental level. I don’t view the middle of the story as being hopeful. I’ve realized that my plots naturally end up with the middle being the low-point, so it doesn’t make sense for it to be the midpoint. I hope this has any semblance of making sense.

Anyway, I’m very new to the concept of actually plotting linearly, and I think it could be useful to me if I knew what was going on here. So any insight would be appreciated!

TL;DR- how would you explain the midpoint, just in general?

Edit: it seems I had some wrong concepts of the midpoint