AH had an online affair about eight months ago while he has trying to be sober and I forgave him. The funny thing is I think he started the affair because he was sober, it's like he let go of one vice and had to pick up another. After that he started drinking much more heavily and had kind of a breakdown in November and ended up in rehab. He came home from rehab and got drunk and hit his head. Enough has happened in the past year that I realized something changed in me and I have had enough.
I told him the next time he drinks, I am gone, period. I don't care if it's six months or two years from now. I am personally just really tired of all the alcoholic crap and ready to be done. He is lovely when he is not drinking but that doesn't make up for all the nonsense I have had to put up with.
Right now, he is behaving beautifully and going to AA every day, probably because he knows I am dead serious. I think everyone is just at a different place in their relationships. Five years ago I would have been like you and much more of a devoted wife but I have been hardened over the years and I am pretty much done. I think if he can't stop drinking this time we will just be doing the same thing in ten years and I don't want to be doing the same thing. I am still fairly young and I have talked to so many women who have been with an AH for 30-40 years and I don't want that to be me.
I hope your husband is really able to be sober and honest with you. You deserve that as a wife. Good luck!