When I was really mean to people it was because I wasn't really happy with myself. I had been jumping from boyfriend to boyfriend and felt like I couldn't be comfortable with myself. I had to take a while to myself and learn what it was that I was unhappy with. I had to change a lot of things about myself before I could be happy with anyone else. A lot of introspection allowed me to be accepting of others and not so mean anymore. In fact, once I was single for a while and went off to New York for a few months and did some real learning about myself, my friends told me that there was an obvious difference. I was told I seemed like a genuinely happier person.

If this is the case with you, maybe you are trying to push people away because you don't feel you deserve their friendship or love. My feelings came from an abusive relationship leaving me feeling like I didn't deserve happiness or love. And once I realized that I do deserve those things, it was like a huge cloud was lifted.