@Kaukations I'm not good at comforting people but I'm gonna try. At least you managed to get into sixth form, and I guess you managed to get into the A-levels you wanted, which means you are smart. Maybe they were just off days, maybe the questions were just more difficult than usual (the Edexcel circle question, for instance), or maybe something else happened that could've impacted the results. Also, GCSE's don't test your intelligence as much as memorisation, though that's what basically all exams are: memory tests, and you are not defined by grades, no matter how many teachers or others try to shove that into your head. Trying your best is all you can do as well, and as long as you do that, no matter what you get, you've done amazingly and you didn't let yourself down at all. Be proud that you've passed, be proud that you've got into college, and most importantly, be proud of how much work you've put in and how hard you tried because that's what matters above all else.
Anyway, I'm going into year 11 this year so I can't let you know my results but it seems really daunting and last year was stressful enough in terms of pressure, so the fact that you even managed to get through year 11 is awesome. Good luck with college and beyond, and keep doing your best.