Sober Sheri congrats on your sober time, and welcome! I think with the birth of this baby and the holidays being here maybe it's time to hold your hand out one more try for a relationship. I find you must always prepare for the worst case scenario so that you are not crushed.
I will share this with you, before I had children of my own my mother and I had a somewhat tumultuous relationship. She didn't get me I didn't get her. When I had my first baby the way I looked at my mother changed forever. With the birth of your own child you can finally comprehend that mother/father's love for their child is stronger then any other bond. Perhaps your son will be able to open his heart to you now.
Reach out! Good luck, be well.