I did the same as you, but in my 40’s. It’s better to start with books that are “too easy” than those that are “too hard” (for your level, whatever that is). I

I did the same as you, but in my 40’s. It’s better to start with books that are “too easy” than those that are “too hard” (for your level, whatever that is). I started with Ken stroud’s ‘engineering math’, then did calculus 1,2,3 and linear algebra at community college (online, with proctored exams), then used chartrand’s “mathematical proofs” to learn proofs, which you must know in order to learn, understand and enjoy upper div math (and Physics). I’m now doing an MS in math and stats and loving it, but you need to pace yourself in a way that you can understand and enjoy the math and physics you are doing - and as many people have commented, that means doing lots of problems . Feel free to message me if you want to chat