I can definitely relate to some of the stuff you've said...I've been wondering the same thing myself. I'm not exactly shy, but I'm an introvert and therefore do not make friends easily or quickly. That being said, once I have a friend, they don't stay my friends long. Right now I'm not sure who my real friends are, or if I even have any.
People do not call me; I have to call THEM. I decided there was something wrong with that picture, so I stopped calling them. One person was my friend for over 10 years, then suddenly decided to stop talking to me.
Another wanted to get together. Everytime I brought it up, she had some excuse. Same with another. Everytime I called her, she was too "busy" to call ME, even after I was willing to be a witness for her in a worker's comp case when she had NO ONE else in her corner.
This is why I joined this forum, along with having a severely depressed boyfriend and needing moral support for coping with that as well.