Have you done much reading on this issue? May I suggest


After the Affair: Healing the Pain and Rebuilding Trust When a Partner Has Been Unfaithful by Janis A. Spring
and

NOT "Just Friends" : Rebuilding Trust and Recovering Your Sanity After Infidelity by Shirley Glass and Jean Coppock Staeheli

They are both v. good books for understanding what you are going through at the moment.

Good luck

V

Never make someone a priority, who makes you an option.