Several things to remember:
1. Just because you are no longer with your boyfriend does not mean you are less of a person or that anything is wrong with you. I'm not saying that you think like this, but in my experience it can happen so I'm just pre-empting it.
2. Being a nice person is aweseome, don't give up on it as there are too few nice people in the world as it is.
3. This chap sounds like, to use common parlance, "a tool". He is an ungrateful sod who deserves to rot in the Seven Circles.
And as for my suggestion as to how to get over him, I suggest getting a shed-load of chocolate and watching some happy films, or even going to the cinema. "Music And Lyrics" is somewhat predicatable, but an ejoyable romp nonetheless and Hugh Grant is rather dashing.
Take courage my dear, you will carry through