I love all the responses in this thread! A LOT of wisdom, experience; what works and doesn't work.
Now: You stated that you are, "Miserable with him and miserable without him". I get that. And unfortunately, that is how a LOT of marriages and long term relationships end up.
I'm going to propose that you do not need to be miserable AT ALL!! Many of us somehow get into relationships and situations in which we feel trapped and cannot get out. Well, we maybe know we could get out, but we don't believe we will end up being happy if we really do get out. We somehow cannot ENVISION ourselves as happy/content/settled any other way than what we've grown accustomed to.
It sounds like you have built a life that in nice in some respects despite being married to an alcoholic abuser. Good on you for that and it's likely that despite your circumstances you've "made the most of it".
But, abuse is abuse is abuse. The abusive part of this man may never change as there are many many abusers of all TYPES of abuse who have no chemical dependency issues whatsoever. Emotional abuse, psychological abuse, physical abuse, sexual abuse, financial abuse, spiritual abuse, not to mention neglect. I have a sneaky suspicion that many of YOUR needs have been neglected all these years. You've met some of those needs through making your home as it is; a sort of refuge. You've invested a lot into that and it's almost unfathomable to let it go. But, that may be what you need to do.
Letting go of something that we once found refuge in is one of the hardest things to do.