I feel so depressed... will I ever have friends?

I'm 19. All my life, I've been back-stabbed by so called friends who were girls. I even lost a "best friend" of 3 years for no reason. I'm just sick of trying to be a good pal to girls just so they can screw me over. I am starting to believe that most (not all) women are fake. :( I could make friends with guys, but that can also be a bit difficult because I have a boyfriend and I don't want to mess our relationship up just because I would hang around with guys. And also, not to sound conceited, but I am I guess you could say "pretty" or whatever and I don't know if a guy would ever just view me as platonic and never ual/romantic. :( I'm so sad, will I ever have friends? What should I do?