I second a PP that Starting Over is an awesome, supportive resource. It started right when I was going through a crappy divorce (as opposed to uncrappy?) almost 2 years ago and I can't tell you how helpful it's been, even just as a place to "hang" on TN.
Your statement about seeing the future you thought you had disappear being scary is very true. I had it happen over night, but it is something you can come back from. Not sure that "what doesn't kill you makes you stronger" is true- I really think I'm a lot weaker from it all. But currently I'm not dead.
I just wanted to give a quick update. My H made an appointment for individual and couples counseling for next Friday, so I am very much looking forward to starting that process.
He also went to his first AA meeting last night - willingly. I offered to go with him for support, but this was a closed meeting, so he was on his own. The best part was when he came home and said he was glad he went and he thought it was really good for him, and he had a very positive attitude about the whole thing.
He also found my P90X dvds and wants to start using those and has asked me to get the schedule for him so he can get started.
He is doing far more than he ever has before. I'm pleased, but still very skeptical since any time we have gone though this before, the changes only last a few days. Then again, he has never made an appointment for counseling or gone to AA before. So those are HUGE steps.
He knows that things are not back to normal after just a day or two. I have made it clear that the effort needs to continue permanently, or I will ask him to leave. So far, things are improving.
Maybe hearing that you will ask him to leave if he doesn't get it together is his rock bottom. I have close friends (we were in their wedding) who are currently going through a very similar situation but with reversed roles, and the threat of leaving was her rock bottom and she is currently in rehab getting her life together. Whatever happens, I hope everything works out for the best, whatever that may be.