As long as things are on a positive note, I have no objections to the situation. Things were really swinging to a low point in your one post, and I was concerned. But perhaps that roller-coaster ride isn't directly related to M, it may be some kind of internal mechanism at work.
It's good that you have an objective outlet for venting, it's given you a chance to keep things positive with M. I can't remember, if you're getting any individual counseling at the moment? It might be something to consider, there's some kind of mood swing going on that can get pretty extreme (and painful), from what I've read on this end.
I just want to see you have more of those positive moments, I feel bad about the really severe negative moments, even though I'm glad Polyamory.com can be here for you at those difficult times. But I have observed what looks like a cycle of some kind, maybe there's a diagnosis that goes/would go with it. I'm just a layman (and not a very knowledgeable one), but I see something there from my distant viewpoint.
I'm glad to hear things are going well again. Please keep us posted on all that develops, whether good or difficult.
Love means never having to say, "Put down that meat cleaver!"