I broke up with her about five months ago because she was clingy in the extreme. I once returned following a four-day camping trip up north to have 19 unread messages on my mobile. I'm just not the sort of guy who's going to want to text a girl every five or so minutes; I like my personal space. Additionally, I'd receive messages along the lines of "Have a splendid day precious, I know mine will be filled with thoughts of you!", and let's be honest, that'd be enough to make Oscar Wilde feel sick.
She didn't take the break-up well, apparently she spiralled into serious depression for a couple of months. I felt fucking awful, but I know that I couldn't have stayed in that relationship. The trouble is, if I reply saying "we've broken up, we need to move on" or whatnot, I'm generally afraid she'll do something that I couldn't live with on my conscience if it happened.