left again

I was recently dumped by the man I wanted to marry. Then, less than three months later, my best friend essentially chose to end our relationship. She made it clear that I mean nothing to her. I have been looking back over my past relationships a lot. I feel like I have neglected the few people that wanted to stick by me. It wasn't on purpose, it just sort of happened. Then, I chose to pursue friendships and relationships with people that were not right for me. Now, at the end of the day, I am alone again (naturally). It seems like my life has been a series of people leaving me. My birthmother, my fiance, my best friends, other boyfriends. I have only had a few stick by me and I know that I push them away sometimes. Why is it so hard for me to just let the people who want to stay get close? I want so badly to be loved by someone other than my a parents. But I can't seem to let the right people love me. I know that I am terrified to be left again, but it just happens, that is part of life. I have put myself in the position to be left alone. I know I don't trust people. Maybe I just chase after the people I expect to leave so that it won't hurt so badly to be left. At least it isn't a surprise when I end up alone. Will I ever be loved? Will I ever fully love someone else?