I agree w/the ladies. He's got to fix himself. Get this divorce over and done with and go on w/your life. The girls want the divorce to happen because they have been thru h@ll and back not having a father there and seeing what you have had to do in order for all of you to survive.
I also agree that he needs to prove to you and himself that he can stay clean and sober for a year. Let's not have another Kourtney and Scott scenario playing out. HE HAS TO DO THE WORK! You can't fix him and I hope you think about all that he's done to you and the girls before you feel sorry for him again.
I know you are feeling guilty, but let's step back and think way back. Did he feel guilty when he walked out the door and left you w/peanuts to live on? Did he feel guilty that your house needed repairs and he wasn't there to help or send money to help? Did he feel guilty that you left your home and moved away? No! In fact, all he complained about was how the house looked when you vacated it....messy! He certainly didn't feel guilty when you had to sell tools, etc., in order to survive.
So, no, do not feel guilty for standing your ground. It's time he man up, do the right thing, and both of you get on w/this divorce. It will never get better unless he seeks professional help and stays sober.
Do not settle for less. You've come too far to settle for peanuts. You are the prize and don't you ever forget it.