right now when she looks at the OM, hes exciting, hes forbidden, hes not sad, hes not making her feel guilty, hes not bringing up the past. Whe she looks at you, it makes her feel bad about herself, you are sad, not as much fun to be around as him.
You have to detach, tell her that you cant make it on tuesday if you arent going to be able to handle the appt. She will be pi$$ed, but whatever. You have got to figure out how to get a handle on your emotions, maybe talk to a doc about some meds, you will still feel your emotions, but it will help you control yourself. When you are able to detach you wont be consumed by this, and you might find that sometimes, just sometimes, you will be thinking of something besides your sitch.
It really seems like this is moving very quickly, if you arent ready to give up then tell her so. Tell her that you think that a marriage deserves more consideration than this, and you have been doing research (really do this) and you are worried about the impact this will have on your son. Bring the the material with you for her. This should be part of the considerations you make when you D and it involves kids. I told my H that I had to know that I had tried EVERYTHING to save us, I would never be able to close this chapter if I thought that maybe if I had just... I also told him that I wasnt comfortable ending our marriage while he was having an affair, obviously he isnt thinking clearly, and I dont think that he is in a place to be making life altering decisions while hes pursuing this affair. I was probably a little harsh there, but I was honest, and it made it clear that I was not ready to give up.
I guess I gave the wrong finger to the wrong man...