Yes, I have this problem too and it's really problematic when I want to have new friends. Sometime, they understand my feeling and they can be good friends but sometime, they use it to manipulate me and I really don't like it. I thing that you should do something to increase your self-esteem. It would be good to change your way of thinking too. When you fill your mind with negative thoughts about you, you can't have a good relationship with yourself and the others. This is some advice who worked for me but, since everyone is different, it may not work with you. You should do your own research on the Internet, I'm sure you'll find some informations that will work for you. The help of a professionnal would be good too.
Black holes are where God divided by zero.