Ive always been a math kid, it came easy and I memorized things easily. But that didn't mean I never studied; the best way (idk if someone said this already) is repetition. Tons and tons of questions! Boring, most definitely but worth it! Also for tricky formulas think of tricks or phrases to help you. Instead of thinking of the letters and signs think of it in a sentence format (if tht works better for you) or some people make little songs or rhymes to remember! Considering your teacher is very by the book I might recommend a tutor or study group so can get different people showing u the same thin in a different way.
Hope tht helps