Happened to me too after 15 months. Yeah, it sucks, but I don't want to be with someone who doesn't love me, despite loving them.
Plus, found out today that there was someone else involved (although of course she said there wasn't anyone else, especially the guy I suspected) as she's finally announced she's "in a relationship" with him. Pfft, I hate always being right.
Just makes me realise I'm soooo much better off without her, despite feeling a little more vulnerable today than I have done for about a month. You'll get through it though, promise. I just wish I didn't have finals coming up in two weeks so I could go out and have some fun and spend some time on me and my mates! My advice is to spend some time being happy with just yourself and your mates. You don't need a relationship to be happy with yourself, so don't jump into another one to try to fill a void that's been created (and yes, I'll stick my hand up and say I've been guilty of that one myself). I've got a fantastic holiday planned with my mates though and am starting a new job in London next year, so I've got loads of things to look forward to and work towards. Have you got anything you could target towards? Say uni or a job or even a fabtastic (it should be a word!) night out with good friends?