Mocks soon!!! helpWatch
Also if you know you're good at something do not waste too much time on it. The short-term confidence boost from doing trivial questions isn't worth it in the long run for the other areas that are lacking.
Don't even stress I got all Bs and Cs in my GCSE mocks then got in to a grammar school sixth form in Birmingham. Just put in like 2/3 hours every day till your mocks and more on the weekend and see what you can do. Then you'll know how much you need to do for the real things.