If you're only thinking of switching to German because you're better at it, don't. A-levels are a lot more work than GCSEs and you really have to enjoy your subjects to motivate yourself to get through it. I'm not saying you don't enjoy German, but it sounds like you prefer English lit. There is a step up from GCSE, as with any subject, in that it's more about analysing and you have closed text exams, but you get used to it fairly quickly and it's not too bad. I got an A at GCSE and was only 3 marks off an A at AS. You haven't got your results yet- you might get an A*. Lots of people, myself included, did 1 or 2 grades better than they were expecting in English lit.