Let her go, agree with her, move on, find someone who will love you.
"I get it wife, I have been selfish trying to get you to stay in a marriage you are unhappy in. I have decided I don't want to be married to someone who is love with someone else. I am going to see a L about getting papers drawn up so we can dissolve the marriage."
It WILL work! but only if you sincerely mean it.
Bomb 8/09. Brief piecing 12/10. D-2/12 Two incredible kids D9,S6 Leading new life! “Success is not to be pursued; it is to be attracted by the person we become."