Em, just remember how he decided to "leave" the M and also his current behaviour...
He's started himself on an "ugly" path, for what ever reason. I don't mean to judge him and I'm sure he has some great, redeeming qualities. What I'm saying is that he appears to be on a self destructive path and it's good you are not directly part of that, right now.
The only person who can change his path, is him. And until he changes that path and starts coming back to you...
Your path should continue to be focusing and working on yourself.
Glad you've been enjoying your time with your roller derby crew!