How to stop yourself from going back

Hi all-

A few months ago I posted about the mentally abusive relationship I had just gotten out of. He called me names such as "whore" and "slut", told me I deserved to be raped and told me that I deserved any kind of negative attention I got if I wore an outfit he didn't approve of. The day after I ended things with him he had a new girl friend. It broke my heart once again but I've found a way to manage and try to keep my mind off of it until now. He broke up with her over the weekend apparently after getting drunk and telling her she just would never be the girl for him and the only reason he stayed for the time they were together was because she was nice.

Ever since we ended things I've thought about him constantly, every little thing reminds me of him, of the good and bad we went through. Now that I know he's ended things with this girl, he's been on my mind even more. I miss him so much and don't know how to flip that switch off. For the first time in my life after our breakup I was diagnosed with being in a depressive episode, and now I feel those feelings coming back because I know I will never be able to be with him again (friends and family now hate him).

I guess where I need help is learning how to stop missing and thinking about him. I don't understand how I know how all the things he said to me were wrong and disgusting, but not feel anything when I think of him calling me them. Why do I miss and want my abuser back so badly?

HELP!