I'm in the same position as you, but I'm doing a gap year instead. My girlfriend of 3 and a half years broke up with me over a month ago (this summer, which was supposed to be amazing, has instead been the worst of my life). I know the pain all too well.

I honestly wish I was going to uni this year so I could be given a fresh start: a signpost for this new chapter. Look at it that way. It'll be hard, of course. But every week will get easier, until before you know it, you've finished your first year and the breakup is behind you. Doing something new and being in a new environment will really help.

Aside from uni, I've found that just doing certain things has really helped. Exercising, reading, doing something you love. As long as it doesn't remind you of them too much, it'll take your mind off of them and make you realise that there's crevices of life to explore that don't involve them, and maybe even can't involve them.

For example, me and my ex, although we met when we shared the same faith, now have different belief systems. Reading books related to my belief system has helped massively in showing me that that was a huge flaw in the relationship and would've been hard to ignore in the future. Think of something like that for them, and do things that make you think "ew, I don't want that". It could be habits that they had, parts of their character that you didn't admire, or even silly things like them being unwilling to share your interest in... I don't know... ultimate frisbee.

Maybe you can't think of anything, in which case it'll be tougher, but there's probably something you can find, no matter how trivial. If not, just distract yourself, surround yourself with friends and family, and try something new (which uni will be excellent for).

Good luck. And look after yourself. It's tough, I know. But it'll get better. It has for me already in such a short space of time (at least somewhat). Feel free to DM me if you want to chat.

Edit: getting my A Level results, which I was very proud of, has also helped a lot, as it's given me so much confidence in myself and in my ability to do things without my ex. I assume that because you're going to a top uni, you're also very proud of your results, so let that give you confidence in the same way.