Hi and welcome.
I just want to say that it is very perceptive of you to notice your son's anger and connect it to his dad's unavailability. Many parents would assume that one had nothing to do with the other, and pretend that their child was not affected by the alcoholism of a parent. I know because my mother pretended nothing was wrong in our house even though it was obvious to me from a very early age that something was terribly amiss.
So kudos to you for having your eyes wide open and not hiding in denial. It's very hard and very sad to realize that your life partner and father of your child(ren) is an alcoholic, but you are one step farther along than most of us were when we started this journey.
L