Can anyone pls. give me an advice(especially an advice from religious/christians people)... thank u...?

I had this ex-bf back in college we were together for 3 years.he cheated on me several times.when we were together I found out he was still in love w/ his ex-gf bec. I saw pics of that girl in his wallet. I just let it ped to keep the relationship going.when we separated schools for medicine proper I found out he had a relationship w/ our clmate/friend.I told him its ok w/ me if he will have the 2 of us as his gfs as long as he will not leave me.But he chose that girl over me.It was very painful 4 me to let him go.I even stopped my study bec. of the pain i felt.4 yrs have ped but Im still thinking of him.I never get involved in any relationship after him bec. its so unfair for the new guy to become my bf if I know my heart still a prisoner of my ex-bf. found out on myspace/friendster that he has a new gf now a clmate in medschool but their relationship is in "complicated" status.do u think he is regretting now of all the bad things he did to me? what should I do?