Hi Jang.
When things go so badly for so long, it takes a toll on our hearts. You don't trust so much anymore, and perhaps you know that its possible that he could someday decide to go back to drinking. The abuse was unacceptable, drinking or not.
A happy parent is the best parent. Follow your heart. He will survive and hopefully thrive, when he accepts and his life continues to improve, without the drinking.
I don't know that you are the author of his unhappiness, but perhaps his drinking brought about this change in your heart. You tried, but you are doing what is right for you, and your child/chiildren, by being true to yourself. Romantic love depends on trust. For me, if I don't trust, I cannot feel romantic love for that person.
best wishes to you and your children, and your AH as well.