Youve given a lot of information on the current situation. Can you give more background? For example - ages, yrs married, kids, etc.
Also, can you describe more about what got your marriage to this point? Your W didn't just start "fishing" around online. What behaviors in you got her here?
Have you read the DR book? If no, get it. Read it. If yes, what are the 180s you are working on? What are your goals?