Tyler, I am so, so sorry that you are going through this. I can feel your pain.
I think it will take patience, which is probably what you don't want to hear. My suggestion is to try to find something that you can connect with. Does he have a favorite television show, or does he play baseball, play video games, whatever it is, try to find something in common that you can chat about. And, continue to talk to him and see him as often as possible. Can you email him too? Persistence will pay off, and of course sobriety will pay off.
Tyler, you're being very hard on yourself. You're blessed that your son's mother is a very good mother, and your son will come around and see that you're a good dad.