Hi
I am not going to outright tell you to dump him. Its not what you want to hear certainly and most importantly its not going to help you have peopel write that. What I want you to do is to think very long and hard and hopefully some of what I have written below will continue that process you have already started. I am not in the business of sugar coating things and will not write that he will be okay in the end because he may not be able to or want to give up drink. That's his decision alone and I would also argue that if he was to seek proper help he needs to do so without you in his life whilst doing this.
Does he also have a lot of drinking buddies?. Where does he do his socialising?. If he was to want to give up booze then he will have to have a complete reappraisal of his life. If he does not think he has a problem with drink then no amount of persuasion otherwise to say that he does from anybody will convince him. You saw this happen with his daughter. Having a go at an alcoholic does nothing; they are immune to such responses. They are also very good liars. You won't get much response from him apart from broken promises to change. They need to hit their own rock bottom and this man has not done this yet partly because he has people around him that enable him to continue.
I think you need to get support for your own self by initially talking to Al-anon as they deal with families of problem drinkers.
I cannot help but think you are repeating a learnt pattern here - did for instance either of your parents drink heavily or were alcoholic themselves?. You are not though responsible for him; he made a conscious choice to start drinking but you cannot stop him much as you'd like to. You've probably seen its destructive influence already and know what it does.
His primary relationship is with drink - not you and your children. That is a painful realisation. Everything else, absolutely everything else, comes a distinct second place.
You probably feel very responsible for him; many children of alcoholic parents do carry a lot of responsibility for others.
He may be "great" with the dc but studies have shown children of alcoholic parents are themselves more likely to find partners who are alcoholic and thus the cycle continues.
What;s better - two people apart and happier or two people in a relationship with dramas played out all the time?. This is a harsh question yes but you need to think about this as well. What are you yourself teaching your children here?.