It sounds like you're doing OK, Cat (at least you were when you wrote this!) A good thing, because it's early days yet. H is still in crisis (MLC). Still crazy. It will be awhile before he comes out of it, so it's good that you are learning to pace yourself. It's a marathon, not a sprint. And you are going to learn so much about yourself! So many good things about your character and your competence that you didn't know before.
About this latest twist in the story -- Cat, for me it's all about perception, it's all how you frame the story, that's how you keep up your strength for the long haul. The use of metaphor to explain your situation to yourself. Sometimes I like to use the metaphor of H being like a beloved dog who has come down with rabies. This may not be a perfect metaphor, I don't know if dogs recover from rabies with treatment or not, so maybe a better metaphor would be a dog who is subject to epileptic fits. But in any case, even though you love and care for your dog, and you know damn well he is devoted to you, you are not going to get close enough for him to be able to bite you while he's having symptoms. It's the same with H. Don't allow him to wound you with his craziness, don't set yourself up for that. You're doing everything just right. It's possible you might have to look at a financial separation as well as a physical separation before this is over, to protect yourself and your kids, to preserve the financial assets of the marriage. MLCers are notorious for being financially irresponsible. The craziness that H is suffering from is not peculiar to him.