I cannot bond with my HFA son

I cannot bond with my son. I have an 18 year old who is HFA. I always knew he was different and very quirky but we never equated autism. We’ve never been close as I have always struggled with his differences. He was recently diagnosed and I am totally broken. It’s like the diagnosis itself shifted me. He drives, cooks, has friends, and will start community college soon but I just do not feel any kind of closeness towards him. Yes I am in therapy but I just feel like such a bad person.