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."
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.