Cheating is the worst thing ever

I started dating this guy from college , I was head over heels in love with him. Since the beginning I got such a strong gut feeling that he would cheat on me and no matter what I tried I couldn't trust him or open myself up to him . He was friends with this girl who I never saw as a threat or anything . 5 months forward I got involved emotionally as well as physically . For a month I went for a trip to USA. I asked him to breakup but he said he would wait . After a month I came back and something was changed he was distant and wouldn't talk to me . I decided break up sex would be the solution but he was so distant and hence we broke up . 3 months later I get to know , he was dating that so called friend I didn't feel threaten to . He wasn't Sexually Involved but Emotionally Yes.

After 6-7 months I tried to go back and make it work with him but I can't do it . I see the girls face when I have sex with him .

Also I can't stop being really really mad at him . He has blocked me everywhere , still can't stop mailing him .

What should I do ? I want him begging me just once so that I can proudly say No