Get some therapy for your affliction called ex girlfriend. At the very least, read the book "The Five Stages of Grief" to help you get through to yourself that it's over and she doesn't care for you. Next time don't break up with someone that you think you love.
Quit clinging to someone that doesn't value you. It's very unattractive and not being much of the confident man that so many women gravitate to.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion