What should I do

I meet this guy not to long and we became very close within a short time he seduced me and went to bed with me and later a lady called me and claim to be his girl friend and I notice he see a lot of ladies he broke up with me but I still love him and...

want him for my self alone

Wait... whats your question? I'm assuming you want him back... but if he's in love with someone else, and he cheated on that person, he might not be that great... he could do the same to you. Maybe you should move on.
Britz