Kyrie, I really think that your H's spew has nothing to do with you. It is all about his issues, and you are the target. There are two separate things that I think you need to think about.
1- is your H seems to be in the midst of a MLC which most likely has NOTHING to do with you and he needs to work this out in his own way, in his own time. That you can do nothing about. So really you need to not think about as much as just grasp this concept and let God take over.
2- right now you are his target, because you are there. If you can find a way, like it seems like you are trying to do, to reduce the tension and get yourself out of the role of "punching bag" that will help you, and also might force H to deal with his issues in some other way. I think this is where you are heading with your communications, I know that you are trying to break the cycle, and I think that is good. But I want to caution you that if he really is in the midst of a MLC that there is no magic thing you can say or do that will snap him out of it. Just continue to validate and get out of his way when it gets too hostile. Maybe "I know you are trying, thank you for that." Or "Thank you for sharing, your perspective is important to me."
This is hard, Kyrie, I wish I had an answer for you. It is just incredibly hard.
