I read a quote in a book a long time ago about how some people are born drowning, and sometimes, you need to pluck their hands off your ankles as they go down because they will take you down with them. Until a few years ago, I thought that sentiment was unspeakably cruel, but now, I think it help save my sanity.
When my H goes down the rabbit hole, he can be an unbelievable prick, but by learning how to detach, I let it ride its course and correct him when he crosses a line. Nine times out of ten now, he steps back, realizes what is going on, and apologizes. I spent a lot of time trying to escape the vortex of his negativity but now I simply do not let him suck me into it in the first place.
It doesn't mean that I don't get frustrated, wished my H's brain functioned differently, want more than I receive... I'm not sure what needs of mine he meets, that's certainly some thinking I need to do.