When will my heart let go?

Hmm. Huuuge chapter of my life has closed, officially. Old apartment is empty. Moved into my new one. I absolutely love my new apartment and this new start. No more living with the ghosts of the past. But I'm pretty sure parts of my heart are still there. I don't want to get upset everytime that I think of him.
Can someone help my heart move the fuck on? But, 3 years with someone and 2 years of living with them during the biggest changes and greatest times of my life is pretty hard to get away from. We moved out of our parent's homes together and spent every god damn night together. The worst part really is that we share all of the same friends. Can't even go to the party I wanted to go to tonight because he is bringing her and I know that the first time that I get to see her that I am going to ruin her ugly face. & I don't plan on doing it at a friend's home. She is honestly the most disgusting and pathetic person I have ever known, really. Ever placing trust in her and ever caring about her makes no sense to me now.