Sounds to me like maybe she just wants to keep tabs on you fella - if she can't be happy why should you be ?!

I have come to realise that many people, if they realise they've fucked up, will jump to blackmail of sorts.

You need to decide for yourself if you can deal with seeing her etc at uni.

The main thing that pisses me off though, is why they have to hide it. If you lose interest in someone, why not just tell them ? a chat about it may be uncomfortable but atleast everyone knows where they stand.