Staying in a uni dorm with a friend and othersWatch
As for what course you should do, it depends what your long-term aim is. Having GCSEs including English and Maths will help you with almost anything; after that then if you want to go to university A-levels will be the best route, if you want to do something more vocational then an apprenticeship or similar would be a good option. Universities don't offer A-levels, you will need to go to a further education college for that, but you should still be able to do that in whichever town your boyfriend ends up in for uni.
I do also share the concerns of Tepper that you are putting everything on hold for him. You say "When we break up" which doesn't exactly show a lot of faith in your relationship! Don't be his housekeeper, and don't give up all your ambitions just to clean up for him - most uni students manage (after a fashion) to do their own chores.