I can only tell you I wish I left at the first, second, third, forth or fifth time I made up my mind. I rationalized it all away, and in the end stayed. for over 20 years.
I am a man of few regrets. But I wish I had the strength to leave long ago. I simply didn't.
The collective wisdom on this forum is amazing. I bet there is over 500 years of living with alcoholics actively participating here. I have yet to read a single post that says: "I'm so happy I chose to stay married to my alcoholic spouse. We had a really long talk one day 20 years ago and I told him I wasn't going to take it anymore and that he needed to quit. Or I was leaving. And you know, he stepped right up, and quit. Our life has been so fantastic in every regard since this. I'm so glad i didn't listen to my fill-in-the-blank who suggest I leave him after his X number of years of abuse."
Never once. Did I miss that thread somewhere?
More than likely, you will look back 20 years from now and wish you had done something. You make the decision. You have to live with it. But go back and read what you wrote. And your path will be clear. They are not like the wine they drink. They do not get better with age. They just get worse. And so do you.