I really suck at math, and noticed that I had to work 2-3 times harder than everyone else in college. I got through pre-calculus, which was pretty damn good for me!
But, I made sure that I fully understood the concepts all of the time ~ especially important because math skills build upon itself! Do extra problems. Read the lecture (in the book) until you really understand what's being said.
Keep on trying ~ you can do it!