Have you ever been used?

This past summer a long time friend came over. For years we had had a love-hate relationship. He had used me once, by going out with me and telling his ex that I tried to seduce him, just to get her back. I forgave him though, but when he came over, he seduced me… He made me think that he loved me. He did it a second time, then he left, disappeared. Then he blamed me when it got out somehow about what happened, telling people I made up sick fantasies about him. I regret it and don’t know how to live with myself. I feel like such a fool and a slut for letting him do that. I’d only had one other sexual partner, and I don’t want that many. I don’t want to feel that way, but I feel so used. He was my friend and I don’t understand how he could do this to me. How do I deal with this?