First of all, I am so sorry that you are put into this position. You must feel out of your mind. Just use this time away to calm yourself down a bit and gather your thoughts together about your world. Don't think of this snapshot of your life now as the blueprint of future life. Circumstances change and people change. Your wife certainly have changed to commit such horrific deed as a married woman to such a wonderful husband like you. But, you know what? That is how life is. It's just unpredictable and so unfair at times.
Since she was so selfish with this deed, try to be selfish for yourself as well. You have committed your life to be married to this woman and vested many years so far. Now facing this situation, if you just walk away, which you have every right to, is that a better direction for you? If your ww has been a selfish and terrible human being and a partner in your marriage even before A, she seems unworth it, especially with A now. However, if she has been a good human being and a trustworthy one before this hickup, it would be a shame to just throw it all away.
I know you are angry, but her confessing her ONS with such utter remorse and not showing a shred of selfishness or attempt to justify her action shows that deep down she may be a good person and she loves you very much, despite what she has done.
To you, I am sure she feels like a "damaged" good, and in a sense she is. But, as damaged as she is, you still have to try to see objectively what kind of woman you are dealing with here. Even with this painful scar that she inflicted on you, she may be worthwhile to be given a 2nd chance at least. Of course, this is your decision and only you would know if she is worth it.
Affair or no affair, there are bad people and good people. When good people slip up and do this, that does not necessarily define them to be bad. And, she will bear this cross for the rest of her life. She can no longer pretend to be the perfect wife nor a faithful wife as she cheated once. Again this will be her cross to bear. So, let her. Pity her for now. But, don't fall to the temptation to have RA, as this cheapens you. She damaged you, and don't make the mistake of damaging yourself further. Maintain your dignity. What fxxking another woman at this stage would accomplish? If you do, she will feel she deserved it and accept it. But, then what? It will come to that both of you had ONS in the end, and how does that leave you? You will be no different. Maintain your high ground and your dignity in all this. Just concentrate on healing your mind and regaining your sanity. It may take a while, but you should try for your own sake.
You can always end this M and walk away. No one will blame you. If I sense that your ww is a bad person doing a bad thing, I would advise you to do whatever you feel right for you. In this case, although I don't know her personally, you may regret leaving her. I sense she has a good character overall based on how she handled this so far, and I am afraid you may regret if you give up on your M with this woman.
I am sorry, man. But, sometimes bad things happen to good people, and you know this. Don't get swept up by your rage and hurt. Try to calm yourself down and introspect things more. You seem like an honorable man, and one way or the other, you will be fine after all this, regardless how you decide and proceed.
I feel for you.
[This message edited by SadCalifornian at 10:31 AM, August 2nd (Tuesday)]