oh, and one more thing. When it comes to love, we cannot decide whom we love. And if we cannot decide whom we love, then inversely, we cannot decide whom we do not love.
So if your wife is in love with someone else, it cannot be your fault, if you still love her, it cannot be your fault. The "easy" part is accepting your fate, and you will be able to do this by accepting hers.
Just cos things are going right, doesn't mean that they were always wrong.