This happened with my mate. He dated a chick since he was 16 til he was 20. They broke up for a week or two once or twice during exams etc. Anyway, they both ended it to not waste each other's youth, cos they didn't want to get married at that age. They then after a few months started hanging out as friends, cos they missed each others company, then one thing led to another and they got back together.
So my opinion is, if its ment to be its ment to be, you will get back together later down the track. So don't stress too much