Rob1971, I know you're probably confused because you came here to save your marriage and now someone is telling you to let it go.
Trust me, this is exactly what you need to do if you are to have any chance of having a R with your W. I wish I done this sooner in my sitch, it would've saved me a couple months of anguish. As it is my sitch was relatively short compared to the many people here who are stuck in limbo for several months or years. Once I followed through with this advice I turned things around within six weeks.
What Rob has told you is spot on. It is counterintuitive but it is what works when there is infidelity involved.
If you love somebody, set them free. http://tinyurl.com/2empx2g