The idea that math skills can't be improved is one of those ancient biases. It would be like thinking you can't improve your body by working out. I was always in remedial classes and now I'm a math teacher with a master's in math planning to go back for a PhD. It's not that I didn't try I just literally sucked at math until I found some good books and more importantly got really determined to understand string theory after watching the elegant universe. It took a few years before I felt proficient but it's inevitable if you practice something everyday. Find a book or YouTube lecture series that is credible and that fits your learning style and you can learn pretty much anything math included