I used to think something major was wrong with me. I made lots of friends but when most of those relationships were tested...most of them failed. I felt used quite a bit because I like to help people out. Took me a while to understand that people will use a person like me and then dump them.
I now have two people I can trult call my "friend." They care to listen if I need them to and give me advice if that's what I'm looking for and visaversa. I still have lots of people with whom I associate, have in my home, help out etc...but they are pretty much in the acquaintence category.