Welcome.
Ironically, one of the first things we learn when we confront the disease of addiction is that we truly are powerless. (I believe we should listen when our intuition is telling us something.)
If it helps, you didn't cause your son's alcoholism. But you'll find that you can't cure it and you can't control it. You can offer support and encouragement to your son...but you may find that some of the things you thought were helpful really aren't. Dealing with an alcoholic is a marathon, not a sprint.
I recommend Al-Anon. It's a support group dedicated to helping the family and friends of alcoholics. It won't teach you how to cure your son, but it provides support. You'll find that you aren't alone, and you can learn just by listening to the experience (and hope) of others. You can find a meeting online. People usually recommend that you go to several meetings before you decide whether or not it's for you. It's been enormously helpful in my life, but it's not an instant fix by any means.
Best wishes on your journey...my heart goes out to you just from remembering where I've been. Keep coming back!