What the Hell Am I Thinking..

You know that ex I'm always talking about. The one who fucked me over. I ran into him yesterday. And we started talking and well...I still love him. I knew that before, but now he knows that. I told him I loved him and I kissed him. He kissed me back. I don't know what I'm thinking...I can't be with him. I have to tell him I can't do this. I have to. But I don't know how...I just..I love him. I like this other guy...This other guy doesn't even want to go out with me. He doesn't like me like that, even if he pretends to. My ex..I miss him so much. I love him..so very much. What's wrong with me?