Expanding, it sounds like you are better off without him. You treated him horribly toward the end? Don't berate yourself. It sounds like he is an unfeeling jerk, he likely didn't notice any change in your actions.
He moved on so quickly? Pity that poor girl and be glad it isn't you.
8 years is a long time. Do you have friends to spend time with? Get out and stay busy. Don't sit at home alone. You deserve much better than that. Take care of yourself.
Yes, you are correct, he sounds like an alcoholic.