Welcome to SR! I'm really sorry that you are going through all that, and you indeed need a lot of strength to cope and clarity to see your future steps. He may not be abusive, but you are simply not his priority. It is hard to accept and understand. Alcohol will eventually become his everything. There is nothing you can do about it. But you can help yourself and save yourself and your children.
And divorce is not such a bad option after all. The consequences of divorce are minor compared to those of having an alcoholic spouse/parent.