I would add that in your situation you have a very good likelihood of recovering your marriage if you take the right steps. You have already taken what is perhaps the most difficult step - realizing your own contributions to a less than ideal marriage, taking ownership of those mistakes, and taking positive action to transform yourself into what your wife will one day consider to be a great husband and father.
The fact that you have shown change in this regard shows that you have what it takes to be in a great marriage. Without introspection, and the resulting changes, some people are destined to remain unhappy.
The remaining pieces of the puzzle are largely out of your hands. You cannot control your wife, you already realize this. All you can do is control how you react to her behaviors. She will have to adjust her dance in accordance with the steps that you take. One of Michelle's basic tenants is that if what you are doing is not working, then change what you are doing. So far, pretending that you are unaware of her affair, and trying to be a great husband to get her love back isn't working. Well, we don't want you to stop being a great husband, so no change is needed in this department. I submit that what is needed is for her to know that what she is doing to you is hurting you beyond measure, and that you wish her to stop. She needs to hear from you that you desire a great marriage with her, but you cannot tolerate infidelity in a marriage.
Do not read into this that I am suggesting you give her an ultimatum. Ultimatums are not boundaries, and you could quickly find yourself in trouble if you gave one.
Additionally, I suggest that before you go to your wife, you let the OM's girlfriend know that her boyfriend is involved with your wife. She should not be kept in the dark, it's not fair to her. She may even succeed in recovering her own relationship which would benefit you. The net effect, however, will be to speed up the end of the affair.
Once the affair has ended, and no contact is established, I think that your wife will find herself (after a period of depression and withdrawl) feeling more in love with you, and thankful for the changes you have made within yourself.
