Try to give him a chance. Find out if he has any personal issues. It's possible he still wants to talk to you but can't bring himself to do it, for whatever reason. Has he had a rough life?
I'm 26 and have lived on my own since 16. Things in my life left me with trust issues and problems opening up. I would show up in peoples lives for a while, then disappear for weeks(or a year) and then just show up like no time had past. In the end my friendships dwindled. People react differently. Some become quite hostile towards me and other would show sadness because they think I don't care.
So try to contact him and find out if this is how all of his relationships are. I know you can't wait around miserable for people like this but it may be worth it.