Getting over an ex

I ended things with my ex months ago but we stayed in contact. He's found someone new and the rational side of me says to be happy for him but the other part of me wants it to end and I'm not the type of person to break or attempt to break someone up. Lately mostly due to dreams I want him back and I feel like I relive feelings of love which makes it worse. I explained my recurring feelings and are not talking. How do I get over him and work on myself?

I've tried hanging out with my girls and I am dating but those are temporary until I get bored or really down and I miss him again.

Thank you

Edit: We broke up bc I went to school and felt indecisive. I realized later on that when I'm stressed I kind of lose attraction and tend to isolate myself. A few days after moving to college I felt void of emotions from him and he couldn't take that again so we eneded it. I was kinda sad at first but school kept me busy.