What to do when you no longer love your husband after an affar?

I have been with my husband since I graduated highschool, almost 12 yrs,been married 5. About a month ago found out that he has slept with two different females.One was "nothing" but the next was a "friendship"for months even before they slept together. Of course I am not perfect and our relationship had its issues, but, I have never been unfaithful despite it all. I know that if he had not been caught it would have continued. Now I feel totally unattracted to him, the betrayal is such a problem for me and do not think I want to continue this marriage. He is not a bad person, but is a selfish person and I dont trust that this wont happen again. Looking for any advice!