I in that i can't get attach and trust my friends.

Hi.
Firstly I wanted to say that I'm not the kind of girl who has a lot of friends . I always had friends that I know since a lot of times because I can't trust people or maybe I don't care about them so I can't stay in touch with them. Even my closest friends I can't trust them , I never tell thing about my life because I think people are egoist , they pay attention only to their lifes and focuses on their own " problems" . Me I always have been a "ream friend " giving them advices, helping them with theirs problems, trying to makes them feel better : and after long years I came to the conclusion that they can be good friends for me because they only think about themselves : but in reality I just don't care about them because they are stupid people for me and I just use and manipulate them because I don't wanted to be alone but now I think I don't need people like this in my entourage , they are just useless. It seems like the only problem in their life is that a boy brokes theirs hearts , but that just futilities and for me this is not a real problem and it irritate me because they are weak, crying all the time for a boy who just don't give a damn about them . Now I don't talk to them anymore : I don't miss them and I don't want to talk to them again. So is it normal that I can't be attached to people suppose to be my friends ?
( sorry for my very bad English I'm a frenchie girl! ! )