Hey, Sad,

I face the same issues to some extent. If you can't let go of things and trying to just ties you up emotionally, then it might be a good idea to try to replace those experiences and the thoughts resulting from them with more positive ones. To do this, you have to go out and meet new people and experience new things. With patience and, I dare say, a little bit of luck, you should be able to give yourself some new positive experiences, thoughts and memories. Those old ones will slowly become more and more distant as your focus centers on your new friends, hobbies, trips, etc.