I am amazed by how closely your situation mirrors my own. I am in college and have been struggling socially. My freshman year, I was convinced that I would make myself available to people and I would finally have the social life that I had been craving for so long; I was somewhat of a sheltered child. I allowed myself to be taken advantage of often when I was young, and I would do nothing about it. When I did "do" something, I would simply give said person the cold shoulder and not talk to them.