There are lots of emotionally vulnerable people at AA or even Alanon. If he goes and decides to pick up some sobbing fool, that's because he's a cheater, not an alcoholic. None of this was/is your fault. He's being very destructive and selfish. Imagine the people he hooks up with. It doesn't work out and they stop going to AA so that they can avoid him. People like him keep others in the drink.