Do you think a person who didn't use to treat you like your H is treating you now could just do what he's doing and not give it a second thought?
Obviously something is very wrong. The pain for him must be intense to go off the deep end like this and be an exact 180 from the man he used to be.
Your H is on a journey that has nothing to do with you. Do you know it is reported by those who have gone through and completed a MLC do not even remember a lot of the things they've done and said? This should give you a clue to how serious a mental illness this is.
L, put the focus back on you. You can't help or fix your H at this time. You can help yourself.