I was in the exact same position as you with English in Year 10 (I was on a 4 at one point). Since the beginning of Year 11, I've found MrBruff on Youtube to be such a great resource. He has a video on literally everything to do with English Language and Literature.. including ALL of the books. The key thing to do (as cliche and boring as it is) is just to do a bunch of practise paper questions. The more you do, the better you'll get. And seriously, that's it. In my mocks I got 7's in English and I was one mark of an 8 in Language... so I can definitely stand by the saying "practise makes perfect" !!!