[chrisseaton]

> I’ve found that even trying to really study through books things like number theory, proofs, and integration takes huuuuge time investments

Well yeah, it's like three years of full-time study to get to an undergraduate level. Doing that part time is going to take you a decade or so. You need to put the time in. I'm not sure there's a shortcut.

There's no 'Royal road', as they say.