Mr B nailed it above. If you want the technical term it’s hypergamy. Google it.
I know this is a marriage saving board but in reality it’s about saving yourself. Mr B and myself as well as a few others have had people try to push us off the board because of our “negative” attitude. When in reality we are just able to objectively see things without any emotions. Your W is not a good person.
What your W did is doing to you is pretty $hitty. She cheated on you that may have contributed to your poor health then likely left you because you were in poor health.
The only winning path out of this it to take the focus off your W and put it 100% on yourself. If she ever comes to you for another chance you can cross that bridge when you come to it. Until then it’s a waste of mental space and energy.