I'm sorry that you have found yourself in this predicament. I'm not here to berate you for what you did...what's done is done.
As for telling your wife, that's a tough one. I don't want you to judge your situation by that of IC and myself, because I don't think what happened between us is true to the norm. I was not treated too well in my first marriage and this led to a somewhat general distrust of men. Then I met IC and he was...well...different. I felt safe with him. Not in a protective sense, but in a trusting sense...he wasn't going to hurt me like I had been in previous relationships and marriage. It was nice. I felt safe with him in being able to be myself for a change, but as much I wanted to believe that general distrust of men was gone...a part of me still felt that. Here is where I feel that we don't fit the mold: One would think that IC's ONS would only feed that distrust, but it was different for me. I saw the internal struggles that he had with the mistake he made...I continue to see it! I don't know if or when he will let it go, and this has had the reverse effect on me and my trust towards men or IC in particular. Today, I can honestly say that IC will never do this again. 6 months ago, 1 year ago, 2 years ago...I could not have said that, so in that sense, I'm glad he told me. Yes it hurts and the thought of him with another woman just kills me inside but time is healing that wound and in the long run, I think it will prove to have made our marriage stronger.
I don't know if I've been any help to you at all Noles. Whatever you decide to do, I wish the best for you and your wife.