Please come on over to the Friends and Family of Alcoholics forum (scroll down the list of forums until you find it). There are tons of folks dealing with a variety of situations although the most common is a partner/spouse with alcoholism.
Your story reminded me of an incident some 30 years ago. I was at my foster sister's house. She had two babies. Her Dad called and I answered the phone, exchanged pleasantries and handed the phone to my sister. She listened for a good solid 10 seconds and hung up.
It was a moment when a lightbulb went off for me; it both shocked me and made me realize that she was doing exactly the right thing. My sister must have seen my face as she said, "I don't like doing this but he is drunk and won't even remember calling me. I can spend my time listening to his drunk ramblings or taking care of my children."
Her girls are now wonderful grown women with children of their own. My sister does occasionally think sadly of her dad. It was indeed sad but I don't think she has a single regret about choosing to focus on her own family and life. She could never have made any difference for her Dad. Her life and family is a testament to her good choices.