I totally get what you are saying. The background info does tend to cloud the issue that this is a textbook affair. Because I know she always responds negatively to pressure, I am not sure if exposeing the whole thing would drive her further away or not.
And "giving her space" works so well, right?
"I need space," to someone who is wayward, merely means "I need you to give me space in which to conduct my affair, unencumbered." How much "further away" can she get? She's already emotionally GONE, and cheating on you!
If you're serious about saving your marriage, you will move back into your home, and fight for it, and fight for your wife. She may scream like a witch with holy water poured on her at first, but she will respect you in the long-run. I can assure you, she does NOT respect you now, and since women tie their feelings of "love" very closely with their feelings of "respect," you can see that you've got your work cut out for you.