To the OP -
I feel confused, and surprised and a bit sad. I didn't get anything from your post(s) to suggest that you are part of the problem, or making his recovery worse. Granted, you know more than any of us here, about your own situation, so you know best...it's just...you seem very sensitive, caring, and attuned to him...you seem to love and trust each other...
I feel sad because I feel that you are blaming yourself when you shouldn't.
Often intimate relationships can, and do, trigger a survivor and force them to confront a lot of their "stuff" so they can appear to make things worse. But that doesn't mean the relationship is harmful...just triggering. It's stuff they need to work through at some point. In that way, it can be cathartic and very healing.
If you love him, and he loves you......I would just ask you to sleep a few nights or a week or a month on your decision to leave.
Lots of hugs to you OP.