LexieCat is right, and I can only say that because I have been doing the exact same thing for months! I keep saying I have had it and I get sucked back in and engage him. My AH acts like his old self for a few days, makes lots of promises and plans, and then decides no one is giving him enough credit or something and says "screw it" and goes off on a bender. He is currently sleeping on friends' couches and I am sure he will call me in a couple of days when he exhausts his welcome and wants somewhere to sleep. He will call me sweet as can be and the second I say no he will turn on a dime and start cursing me out and telling everyone who will listen that I am an evil b*tch.
I did take a step though, I am putting the house on the market. I can tell this isn't going to improve with him. I am glad you are considering moving. Right now you are mad and determined but just be aware that once the anger wears off you will start to reconsider, especially if he's nice for a couple of days...