I have a very good friend who went through a mild MLC - if that is the word. One of the things he told me is that you want to punish your spouse because you feel trapped. Maybe he resents the fact that you are OK and he isn't.
Only you can decide what matters most. The law in divorce is almost always unfair. MLC impoverishes almost all of us, except those who go through it young enough and quickly enough to put things straight. They either blow it all on the other person, and/or quit their jobs and then impose a divorce settlement on us that takes no account of their wild spending! It is just another of those things. Personally I would take the hit [I am in fact taking the hit], but I am not you.
He still sounds remarkably immature and unwilling to take any responsibility. feeling guilty isn't really what it is about, is it? it is doing something to try and put things right, and then if you can't, trying to make amends.
it is tough. I guess it is good you are talking. Ending it because HE isn't doing anything does not turn him into the good guy, He knows that and you know that. Emotional coldness and failure to engage in therapy aren't about being Mr Nice Guy.
I don't know what you do about stuckness - perhaps someone else has some ideas?