Hey, I've been reading your thread, and yeah, I agree with you, you do need to stop it. And relax.
I am writing because I was your wife (in her position) four or five years ago. We have three kids, and we were basically kids when we got married. My husband and I did not always handle our situation well. We often made it worse for ourselves. After he discovered my affair, I did not have the strength to end it. After all the anger, the ultimatums, his attempts to stay in control, my husband began to have affairs too. This went on for a year or so. I am not saying this was right, but we both endured a period of settling for less (less than we deserved in our marriage relationship) because it beat the alternative: separation and divorce.
Still, in all of that chaos(and it was worse than chaos), what kept us together was the fact that we both really did mean it when we took our vows, even if we weren't acting like it. We both still felt like we made the right decision in getting married. We both genuinely wanted our marriage to work. Neither of us really wanted the ugliness we were creating for ourselves, but we found ourselves stuck in it for awhile. Without that desire (to stay married), it would never have standed a chance.
In the past five years we've seen five different counselors! The absolute worst was an addiction counselor who prescribed tough love and treated me like some sort of monster. It was so bad, even my husband couldn't stand it. We finally ended up with a woman in her sixties who has much wisdom and life experience. It helps when your counselor has a firm grasp on reality, on why these things happen. We have been seeing this counselor for the past three years. We still go, although our lives have settled, and we are happy. It can take years to sort it all out. That is the bad news. Right now you are feeling like you can not deal with it, and maybe working it out is not an option for you. I am only writing to tell you that it can be done. Detachment is easier said than done. If your wife can not detach from OM, then I would advise her to try to be friends at a distance with him (almost everyone will tell you this is a bad idea). But maybe then she can begin to see his faults and come to her senses. It may take some time, but if he begins to get frustrated with her, it will cause her problems that she probably has not bargained for. She will begin to see that grass is not greener over there. Whatever OM is bringing to her life, she needs to learn to do that for herself. That can take some time.
But then, if your marriage is over, it's over. I just wanted to offer you a different perspective and let you know that in some situations, the pat answers and formulas don't work well. Take care of your self.