leelteloo, if you fell down, would you say, 'oh, stupid me, better stay down here!'. Or would you try to get back up and carry on?
You can't get back the years you've spent with him, but you have a helluva lot of good years ahead of you. You have the right to enjoy them.
Do you really want to spend those years with him?
Do you want your children to see marriage as being between an unhappy woman and 'a selfish binge drinking waste of space'?
If everything is wrong in the relationship, and you're unhappy, then staying together will just make everyone miserable. Don't fall into the trap of staying for the children. They pick up on every nuance and it will create a horrible atmosphere for you all. I don't agree with the term broken home, but I can say from experience, I'd rather be from a broken home, than living in one.
If the only thing standing between you and happiness is an exit strategy, then post on the relationships board and women who have walked that path can offer you tailored advice.