I know how it feels bro, it's terrible. My ex was my best friend for almost a year before we went out, and now it's like we don't even talk.

It's a horrible thing to go through, but to get over her you really are going to have to cut her out of your life until you're over it, then you can gradually introduce her back into your life, and hopefully become friends again.

Trust me, even the smallest things, like going to her facebook, sucked me right back in and put me back where I started. You gotta just not see her, talk to her, think about her. I know, it's easier said than done. It took me months to get over my ex, but just know that in time you will feel better. As cliche as it sounds, you WILL find somebody else, your life isn't over. Just try to be with your friends as much as you can, and when your mind starts to wander to "what could have been," stop yourself. It can do nothing but hurt you.

I wish you the best of luck man, feel better.