On some level, I think he KNOWS he's not good for you. Who knows why he said that - I suspect he started back up with drugs, or with OW, or OW found out he was with you, or who knows what.
Maybe he's salvageable, maybe he's not - but I do know this: He will NEVER step up to the plate until he LOSES you. As long as he can still play these back-and-forth games, he'll never grow up.
If he contacts you again, tell him the bar has been raised - now it's FIVE YEARS of good behavior on his part, and then you'll THINK about dating him IF you're still single.
Moving on shouldn't be hard, now, hon - now he's PROVED to you he's not capable of being what you need.
