Remember that there are going to be good days and bad days. Days when you are saying all the right things and days when she pushes a button to make you say all of the wrong things.
My wife and I went through the exact same thing while I was gone. She told me she was pregnant and said it was mine since she claims no PA with the OM. I supported her the same way you supported your wife's decision, whatever that may be. That is pretty much all we can do is be supportive.
Remember that she is living in a fantasy world right now and that it is going to take time for her to see things as they are not as they were. This is how my wife is living now be it long distance.
I don't know if I helped much but you can always say that prayer to help clear your head and make a good decision.
TT
M 34
H 34
Together 8 yrs
Married 7 yrs
Son 2 1/2
Son 2 1/2
SD 12