Let's be honest with ourselves here. Only a small portion of people reading this thread will have the diligence and work ethic required to pull off a brilliant performance like OP. Realistically, they're an anomaly.
I got an A* at GCSE maths, from being in bottom set of the year. It got me super motivated, I realised that I had so much capability within me. If I can do super well at GCSE, surely I can overcome A-Levels? Ah yes, foolish younger me.
So when I got a B at AS, and was predicted a lousy C by my teacher, I got brave. I too thought I would rise from the ashes like a phoenix. By April I was brisking through the hardest past papers with ease. I felt like I had an A* up my sleeves, I was SO ready to show my maths teacher my results slip in August and see the look on her face. I smashed my mechanics, but flopped core maths. I was traumatised on the days of the exams. I only ended up with a B overall.
I'm sincerely not trying to be bitter here. I'm giving some sound life advice, if you're willing to take it. A-Levels aren't like any other challenge you might face in life, because the fact is the exam boards are unpredictable. You could be a clever and hard working student but end up with a poor grade that doesn't reflect your true capabilities. Having your heart on Oxbridge or getting strings of A* grades is a sure way of possibly setting yourself up for disappointment.
Nobody is going to judge you for your A Level grades. They're not even relevant once you're in University, everybody forgets them just like GCSEs. I'm going to a prestigious 14th Century University in arguably one of the most beautiful cities in the world. Simply work as hard as you possibly can on your studies, and then look over your prospects when you know what you've got to work with, not the other way.
Good luck to everybody going into Year 13.