Lunchbox, you mentioned in a previous post that your kids aren't little anymore. If you can't focus on leaving your husband, perhaps you should focus on minimize your children's contact with him, especially when he's drunk, which frankly could be any time at all.
I mention this because this is might be the perfect time to establish healthy ways of detaching. By the time I was in high school, I figured out pretty much on my own that if I hung out in the library and signed up for every after-school activity known to man I could avoid the house as much as possible. It certainly made me a stronger college/scholarship candidate. My sister, on the other hand, figured out that she could avoid the emotional turmoil via drugs/alcohol/sex.
You may not be able to leave on your own at this point in time, but you can lay the groundwork to make it much easier for your kids to do the same. My sister and I were left to our own devices, and as you could see results varied greatly.