I'm doing 4 A levels this year and am struggling to find the time for revision too. But I'm making sure I understand everything I do in class, so it makes it easier for me when I revise it. I'd ay just try not to stress about it, and take each week as it comes. I tend to also read ahead before the lessons. It means that I will at least have some knowledge already.In terms of revision, I do it when I can, I get my homework done first so I don't end up swamped with it and then revise afterwards. I usually do bits of revision and reading in frees so I can do my longer homeworks at home. Perhaps, if you don't already, try doing homework across the weekend in little bits, instead of leaving it all for one day. I do maths homework Friday nights and then other short homeworks Saturday nights, and the remaining on sundays. Then the time I have left on a sunday I use to revise. Good luck, just keep up the effort and you will be fine!