Florrie + Remus
You need a healer and the problem is that any healer (or me) is a mandated reporter. I've already reconciled myself to not reporting Order business but we need another full-on healer.
Did he do something under torture? And [...] this is why I think we need a full healer: do you think he could be under the Imperius?
If he did something under threat or under magical compulsion even if it's what I think a deep betrayal it may not be his fault completely. You can't help how you feel but maybe consider that before you act and don't take it up with him. Ask for support for your own troubles about what he did elsewhere. You're a secondary victim.