I have read your entire post OP. Let me see if I understand correctly (please correct me if I am wrong): 2 years ago he showed some physical interest in you but at the time you did not ask him to explain his actions as you said you were shy. At some point in the past you had a sexual relationship with a different guy and you said you feel bad about this. Recently, in the past couple months, when you finally asked your friend about why he showed physical interest in you 2 years ago he responded in a mean way. It sounds like you bringing this up bothered him so much that he wants you completely out of his life. Is he still dating the person he was dating in February? It sounds to me that he has found you a bit too pushy lately and he just wants to make it clear that he is not interested in a relationship with you. If he feels this way, as his friend, you need to respect his decision.