I'm sorry your friend did that. I had "friends" like that and I stopped talking to most of them. I felt a bit lonely at first but I found other friends and got closer with my healthier friends, it was a turning of a leaf.
Your friend sounds very competitive and probably just wants as little competition as possible. Photography is very competitive to begin with and he sounds pretty cut throat. He's still a douche though i'm not making an excuse for him. If you want to stay his friend just don't expect much. I wouldn't share things with him about any future competitions or anything. View him AS competition.