You haven't been a pain-in-the-ass. You've simply been afraid of doing the hard things that need to be done, in my opinion. That's understandable -- it's damned hard.
I don't believe for a minute that your wife is done with OM. She is very likely either lying to you about that (remember -- all cheaters lie), or she has temporarily broken it off with him (or, more likely, he has broken it off with HER). Separations rarely lead to reconciliation, and the problem is, you will not have an opportunity to "live the new Lynn" in front of her on a daily basis, and shine a light back to your marriage.
My suggestion would be to tell your wife that you don't want a divorce OR a separation, but that you can't stop her from doing what she feels she needs to do. I also think you should expose her affair to both immediate families, so that maybe those that are supportive of the marriage can exert some influence on her.
WHATEVER you do, get some good legal advice, and make sure that YOU are not the one to leave the house. If she had (is having?) an affair, and "needs space," let HER move out.
