My baby boy

Turned 20 last week, seems like just yesterday I was holding a screaming Buddha of a bundle in my arms, my perfect little boy, not 20 years ago.

I would like to say he has grown into a fine young man, but I can't because I don't know if he has or not. I have not seen him for almost 7 years, I have not spoken to him for 2 years, not from lack of trying, but because he chooses to ignore me. I can say he has done well for himself career-wise and is now a project manager for a web design firm in NZ, something he has shown a keen interest in since he was 8 or 9 years old. I only know this because I read it on facebook, I also know he classes his step mother as the only mother he has, also read on facebook.
Yes it tears me apart that we don't talk, it tears me apart that I have no idea as to why he has cut me out of his life, it tears me apart to see him telling his friends publicly for the world to read that his biological mother is dead. I guess he has his reasons, and one day in the future I may know what those reasons are.
Until then all I can do is continue to try and keep contacting him, it is up to him if he answers or not, I can't force him into doing something he doesn't want to do. I would like to know what it was I did 2 years ago to make him hate me as much as he does.
I love my kids more than they will ever know, they are my world and it breaks my heart to know I can't have them both here with me. I would give up my life to go back 10 years and change things, but I can't.