This happened to me last year, but thankfully on the actual test I scored a 19. I felt that bootcamp and destroyer were slightly more difficult than the actual exam. Categorize the questions you are getting wrong and learn how to do those types of questions. For me it was probability and statistics cause I never took a class in that, so I just practiced the different types, and went through the process of how to solve each of the types. Also, make sure you study the math formulas. Knowing them could save you time to work on problems you think are more difficult. I think there's a list in destroyer or on bootcamp or chad's videos. It's out there somewhere!
Good luck, I'm sure you'll do great!