I am in agreement with Cadet...nothing is going to change the course of your spouse's crisis. Yes, he may say he's interested in reading about mlc, but in all honesty, he might read a chapter and toss the book aside. Your h has to help himself...you can't do it for him. The broken "self image" was not done by you, therefore, you didn't break him, you can't fix him.
Educate yourself about mlc and depression. The most important things are: your finances, you and your family. The focus now has to be on you and your family. Again, you can't fix him.
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.