Renee,
As an alcoholic who's wife divorced him, I say, do not feel guilty at all. I wasn't even given the opportunity to change. Just divorced. I wasn't abusive verbally or physically. I was just distant. No lies or secrets.
And while I do have resentments over her not giving me a chance to get sober, I don't blame her for leaving me. She has no guilt over it (though she always did care more about what she wanted lol). And she quickly started dating another man and she's quite happy. I'm the one who messed up. I'm the one who has to live with the guilt of my actions.
You have nothing to feel guilty about. You obviously gave him more than enough changes to change and he put booze over you and worse, his children. Move on and feel GOOD about it.