Letting go huh? It's one of the most difficult things a person has to do...
One gets used to something, it doesn't matter if it's good or bad, if it's constructive or destructive, if it's fun or not, if it leads somewhere or not, if it's cuddly or yucky, you just get used to it/him/her... So after a while you realise it's not okay, the whole thing doesn't do you any good, you have nothing to gain from the whole thing, it leaves you empty and miserable (I am listening to Korn, Alone I break... it might have some influence on me or my subconscious at least). The deal is that you have to move on, you try desperatly to hang on to the last inch of it by any means, you even do things you wouldn't normally do, but it doesn't work. So finally you realise you kind of made a fool out of yourself for nothing and then you start to think that there are so many things/persons/whatever which/who are more worthy of your attention and of your energy you are wasting. So you let go. End of story. It is still painful, you will think about it for a while, you will still speculate of what might have been, but you finally stop trying to work things out. And something good will follow. You know it will, it's just a matter of patience and time. If you manage to overcome this fucked up state of mind and of being, you did it, you just fuckin' did it. And life goes on!
Emotional shit, drama queen stuff, call it what you want, life is one great thing ^_^