Here's what i did. It's been a month and i feel a lot better.
1. Avoid her like the plague. All communication, seeing her etc.
2. been on holiday with good mates. Had a laugh, just had lotsa fun out of my usual routine.
3.flirt and go out with other girls. Whether they're girlfriend material or not, it help to know there are plenty of others interested.
4.time. Just give yourself time, and try to stop thinking about her. Feeling angry, and hating her is fair enough. But [bthat] should also make you realise that it was never going to work, better to break up now then even further down the line.