WAW in OC = I'm sorry to hear your situation. I know all the hurt, pain, confusion that is going on for you right now. The only advice i have is for you to LISTEN, and don't disagree with her feelings. Someone once told me ANGER and GUILT are opposing emotions. By her being ANGRY at you, she doesn't have to feel GUILTY for what she is doing to her family. Anytime you try to convince her she is wrong, the defense mechanism kicks in and you are in trouble. So listen, and try to validate her feelings when it comes to how you treated her in the marriage. As far as her affair with a 22 year old, that may just be a boundary you set in things you are willing to talk to her about. If she is like my wife, she will say the affair is not the reason she wants out of the marriage (although its the reason she won't work on the marriage now), so by standing up for yourself and letting her know calmly that you won't discuss him, she will most likely respect your wishes.
Patience - also did you post your full situation anywhere?