I wanted to add a little something for the original poster. I've been in a similar situation myself. My DH is an alcoholic, and he goes through periods when he is more or less functioning.
All of these responses for you to leave are really from people who are trying to look out for you, but I remember being in your situation and the wall of fear that would come from this kind of advice. The best advice I ever received was from a therapist who said; "When you're up against a wall, don't run right int it. Dismantle it brick by brick."
For me, this meant to start the moving process. Get rid of all of my extra stuff and reduce my burdens and ties. Fantasize freely about what you want, and begin to think about how to achieve it. If it was only you and your kids, where would you live? How would you live? Who would you want to have close by? Etc, etc etc. For me, coming up with a plan and putting it slowly but steadily into place gave me hope. Every time I was mad, I could do something about it. And as the end of our relationship began to look like a beginning instead of an end, I grew more of a backbone. I stood taller, smiled more, felt less bogged down, felt hopeful, ...
No matter what happens between you and your husband, you can improve your situation best by embracing your independence. Marriage first means learning to be a couple. Then it means learning how to be yourself in that couple, and letting him be himself. Let his actions have consequences that don't involve you.