Omg what a manipulative, delusional a*hole! Sorry but that's the polite version. You did NOTHING wrong. His recovery (and he does not sound recovered in the least) is HIS responsibility, not yours. He put you and your kids through hell. He put your kids in real danger. Getting this active A out of your house was the right and safe thing to do.
now I have ruined it by being a complete bitch
So keeping your kids safe from a drunk driver, from a father who constantly "forgot" to pick them up, who let them find him passed out over and over is a bitch? I'd call her a good and caring mother. Ruined what, a life of chaos, drunk driving, lost jobs, ugly scenes in public, guilt trips, manipulation, endless fights and lies, verbal abuse, one broken promise after another?
Stick to your guns, lady, and refuse the guilt trip. It's typical alcoholic bs. I'm sorry for your pain. I understand this dream you had of a life with him is a painful thing to lose. Sadly, addiction kills a lot of dreams - but there is a lot of life left afterwards and it can be a very good, happy and peaceful life. You deserve that.