Remember that prediction grades are not definite and by using your time effectively you can drastically increase and grow your grades. When I was taking A-Levels, my actual grades were far higher than what I was predicted. The time between the A2 mocks and A2 exams, I regularly drilled past papers as I had understood most of the topics by then, therefore, I just had to apply the knowledge I had into the actual exam paper.
If you don't mind me asking, do you have revision techniques that suit your learning style? If you do, I suggest you stay consistent with it and I'm sure you'll get higher than what you were predicted. Do you have any universities in mind that you want to apply for? Are there entry requirements higher than BBC?