I TOTALLY understand this 100%. Do you ever have section quizzes in your class? If you do, I've found it's helpful to get the correct answers, fold the answers over, and retake the quiz. From there, you can see what you need to focus more on. Maybe it's a particular concept that you're having trouble with in a chapter that you need to look over again? This was the biggest help for me.

Also, does your professor offer any tutoring sessions or anything? I've found that the on-on-one attention is extremely helpful as well.

I wish you the best of luck.