With math, is it arithmetic that gives you trouble or the actual symbolic manipulation of mathematics?
I am hot garbage at keeping track of numbers but turn those fuckers into letters and (at least for me) it's off to the races. Then I just convert everything back to numbers in the last step before jamming it all into a calculator. This method saved my ass in 400-level biochemistry courses. (Annoyed the shit out of the grad students grading my exams, I'm sure...)
You may be better at "math" than you think :]
Good on you for just casually getting a computational physics degree without inherent math talent... like holy shit that's impressive!
I have also cried over coursework on linear algebra as well as electricity and magnetism :') Brutal stuff.