Dude, don't sweat it. About two or three weeks back I posted on here about my feelings towards my ex-girlfriend and how I felt "lost" without her. With the advice of people on here, I went and told her how I felt.
During spilling my guts to her I realized that I am playing myself for a fool and there is NO REASON that I should feel so strongly about someone if the feeling isn't being reciprocated (sp).
Funny how things have a way of working themselves out. I've since met this amazing WOMAN who is confident, successful, loves to run, and enjoys the things that I do. We're having a blast together and the thought of my ex rarely pops in my head now.
Stay strong bro. I was just there! I know it sucks, but don't get down about it! Hang with your friends (don't talk to them about her because it will piss them off if that's all you talk about)and keep yourself busy. It will work itself out. Trust me!