Puppy is your story on her somewhere? I would love to read how you worked through it. You W sounds like mine, and I am also a thinker. I research and analyze every angle of everything...which probably gets me into these messes.
The biggest issue I'm having is do I fight or do I let her go. I know if I fight I can win, but is it really a win? Will she grow as a person so we can have a mature relationship? Can I let her go? Can I deal with her going farther into the OM arms? Will she come back to me or is he the one for her?
I think you'll find our backgrounds, and our approach, remarkably similar.
Do you fight or let her go? That one's easy: you fight for your marriage, BY "letting her go" to a certain degree, and for fighting for her at the same time. Why?
1) God hates divorce;
2) YOU don't sound like you want to be divorced;
3) Your wife, believe it or not, is likely LOOKING for you to fight for her;
4) It will make you more attractive to her;
5) It will make you a better spouse to someone else in the future if this doesn't work out;