I'm so sorry to hear about the latest developments, Tears. I was so hoping when he had that talk with you that maybe, just maybe, there would be a better ending then we mostly seem to hear about on here. Is it possible that he started drinking again BEFORE the MLC really took off? I work with an alcoholic who is such a smart, together person when he is sober. When he falls off, he becomes so totally different!
MLC is such a hard thing for them to get through on it's own. When you add in drinking it must really make it so much harder. My oldest D18, had a bad time when she was 15. She was acting out and we went at it a few times but I never would have spoke to her like that. I remember one time I cursed at her after I found out she snuck out and spent the night with her boyfriend when she was supposed to be at a friends house. I STILL feel bad when I think about that.
I now know that a big part of her acting out was her mom. She had started to spend all her time at work and with her new friends and never had time for her. But every time I tried to set boundaries with my D, my W would step in and over-rule or undermine me. It was the one big thing my W and I fought about. After B-day, I stopped letting my W influence or over-rule me with her and she (D18) and I have a GREAT relationship today. She wanted boundaries and when my W started wanting her "freedom" felt badly about not letting her live the way she secretly was wanting to live her life. She graduated from a really excellent private HS this year with a 3.6 GPA.
It sounds to me like your H isn't ready to come home as hard as that is to realize. He isn't done "baking" yet and coming back now might be the thing that seals the END of any hope for the M to work. He needs to get a handle on his drinking and start to deal with his MLC more than saying "You were to blame".
The one good thing I see (although I'm no expert, remember that!) is if he does want to come home, really does, maybe that will help him to start dealing with his own problems. It sounds like he has at least started to see that just running away won't work and he isn't suddenly "happy" because he left you and his family.
I wish I had more or knew how to help, truly I do Tears. Just hang in there and keep believing in YOU. I hope your S is OK now and remember your D15 needs you now more than ever. I'm praying for you!