Have you arranged for some therapy for yourself yet? An internet list is not a substitute for the real face time connection you need to process your feelings right now--a qualified therapist could really help you.
I'm still baffled at my own addict's choices--she's dead now over 9 years now. I never got answers when she was alive or after. Most of us don't. The only thing that will help is taking the focus off him and putting it back on you. You cannot understand what your husband most likely doesn't understand himself. Logic is not part of alcoholism.
There is no "answer" that will make sense of this. I really think continually asking this question is destroying any chance of peace or healing for you. I am speaking from my own experience, and from many accounts I've read on this list.
Get some therapy, get the lawyer, and start the legal process to get him out of the house ASAP.
Take care of you now--he sure won't.