Should I leave him alone

I met Bryan in my automotive class in the spring of 2011. We got each other’s phone numbers and started talking on the phone. I found out he was in a gang and that he had done terrible things in his life [murder, robberies, etc.]. That didn’t matter to me; all that mattered to me was who he was. I accepted his request to date around the beginning of February 2011. There was one time while we were dating that he told me he had beat a guy with a baseball bat. There was another time he forced me into a room and started kissing on me. I told him that if you loved me you would stop, and he did. I ended the relationship because I was worried about the gang situation, and what it could do to us in the future if anything at all. After I broke up with him in April it hurt so badly, because everything in the relationship was great except for the gang stuff.
I started dating Drew in June of 2011, but no matter what this guy did I couldn’t get Brandon off my mind. I was trying my best to forget about him. I was making progress when all of a sudden out of the blue he would text me again and the feelings would come out.. The relationship with me and Drew didn’t last because all he wanted me for was sex. I ended the relationship around the end of September or the Beginning of October. I may have been wrong for not giving myself time to heal completely from the first relationship, before jumping in another one.
He was still on my mind. (Bryan) But as I spent time with others and began focusing on me and having to deal with other things I would start to get over him a great deal. I started dating another guy Robby in December of 2011. I forgot completely about him at one point [Bryan]. Then around Christmas he text me back. (Bryan) His ex-girlfriend warned me that he wasn’t worth the pain I was going through thinking about him and stuff. I didn’t even know her. When he text back I didn’t have feelings for him at first a lot, I knew I was over him for good. But after talking to him again they can back as strong as ever. I broke up with Robby because he seemed to only want me for sex too. Bryan helped me to see that. But now that I am single again he doesn’t seem to be talking to me as much as he did when I was in the relationship. He told me that he was enjoying being single, but he text me back first. I know he just broke up with his (Bryan) girlfriend in December, but he text me back after the new year began, what does he want from me? Does he want me or not? Or is there so sort of game being played that I am not aware of? I want to be his wife some day because I still think I am in love with him, but now I am not so sure because of what is going on. I am so confused. I just want to know what do I do?