Re: I should have listened to the advice given here!
I confronted her with the new information I found and explained why it was the last straw for me. She got very defensive and insisted they were just friends and it was never physical. I told her that at this point, what she says doesn't matter, because everything I know I found out on my own, and every time I dig deeper there is more. She never came clean about anything on her own.
I also told her at the very least she had kept a friend that I asked her to stop talking to on a few occasions over the last year and she promised she had. She lied to me, went behind my back, and went to great lengths to hide the relationship from me. Regardless of what else I don't know yet, that was too much already.
She insisted she has been trying the last few months and has had no contact, and she even said she would have a polygraph. She felt the past didn't matter, and there was no need to go into more details about her lies once we reconciled.
We are going to talk again tonight, but at this point, after 20 months of marriage, if this is what I have to look forward to, I feel like just giving up and moving on.
Thanks again for all of the feedback.