The basics for the walkaways and the mlcers are pretty much the same. From what I've read of your postings, it does sound a bit like MLC. You have to remember, your h didn't complete his crisis previously and this time around, it just may very well be different and more intense. Time will tell if he's in MLC or not...but you need to give him plenty of space, listen and validate him. He may try to bait you into arguments, but try not to take the bait. If he does bait you, just say "I'm sorry you feel that way" and let it go.
Keep the focus on you and your children.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.