Of course you feel angry, betrayed, hurt, and abandoned even though you left him because he abandoned you, the relationship and the family long ago, didn't he?
And of course you are confused. You have been mired in the sickness of alcoholism and addiction for how long now?
And you're afraid to let go. And one of your excuses your brain makes up is the fear that once you are done, it will make him see what he has lost and finally get sober, but then it will be too late because he will find someone else. These are all just fears. They are not real. What is real is what is happening, and who he is TODAY. Not tomorrow. You have to learn to stay in the Present Moment. We have no crystal ball. He is not likely to all if a sudden have an epiphany and need to get sober, change everything about his life, and stay sober. And anyway, it's not a good idea to arrange our lives and make our life decisions around an alcoholic and what an alcoholic may or may not do. Because they are chaotic and unpredictable. Unstable.
You have your own inner compass, don't you? Remember back to when you used to rely on and follow your own inner compass. What did it tell you you wanted? Where did it tell you to go? What was important to you? Find it. It's there deep inside of you, buried in layers of sickness.