Also, could you say a bit more on "I believe the affair is still going on as of last weekend". Have you set your boundaries? Who "filled in the blanks - your W? Knowing the baseline of your sitch and what you're dealing with, as well as thinking through the boundaries you can / cannot live with would be a start.
Do you have any kids and how long have you been together?
Me 42 W 39 Married: 11 Jan 1998, T: Since 1992 First Bomb: Sep 2007 Confirmed A/OM: 4 Nov 2007 Kids: D10, S5 Reconciled and together again after (alot of) time and heartbreak. 3rd kid, S, born 2 Jan 2010.