I may be off base here, but it sounds to me like you just aren't interested in the subjects. One of the biggest factors to learning is how much interest you have. There are tricks you can do to get yourself more interested, but it does take a fair amount of work and isn't always effective. But if you wonder why sometimes we can remember silly details or whole complicated plotlines from stories but can't remember a simple math formula, a lot of it is actually your interest levels. Your brain prioritizes the stories because it is interesting, you can relate, and thus form strong neural connections. It is much harder to do that with a math equation that is fairly abstract and not in constant use.

So I would start at finding which thing interests you the most. What meets the job criteria that you are looking for BUT also excites you? Then focus on moving in that direction.