First off, you're extremely lucky to have the "Vets" you have giving you advice. Especially Sandi2's advice! I'd kill to have a WAW's perspective on my sitch, especially as early in as you are.
From what I can CLEARLY see in your situation... You're EXTREMELY confused.
I get that. Holy Cow do I get that. Read my sitch to see just how deeply confused and upside down I've been over the last few months.
But you need to know this: With how confused you are right now... With how much vacillation you're doing on your situation and how your brain just spins and spins and spins after GALing... you need to RELAX!
Listen to Cadet's very first post about TIME. You've got it here, even if it doesn't seem that way. You need to make sure that you're giving yourself the time you need to digest your situation and figure out the best path to take FOR YOU.
You're getting a TON of great advice. Again, I know what it's like to get great advice, but not want to listen to it because "My situation is different". Hell, everyone on this board knows what that feels like.
But you need to come to grips with some things before you make any life-altering decisions. What is it that YOU need to do to fix YOU?
You talk about going dim, detaching, GALing... All things that are GREAT ideas and I wholeheartedly agree you should be doing... But you haven't given ANY of them enough time to make the changes they'll make in YOU.
You, just like me (and almost everyone else here at some point) seem to be doing these things to win your W back. In fact, you're at the point now that it seems like you're willing to go through with a D to prove a point!
Trust me and the hundreds of other posters here: EVENTUALLY, your GALing, your detaching, and your 180s will, at some point, begin to make a difference in YOU! You CAN'T do these things to prove a point to your W. You can't do these things because you want to show her something. These things only work because they help you discover who YOU are and the person you can become.
As far as confronting your W about the possible OM... Well I'm not sure I'm the one to give you advice on that one. If you read my sitch, you'll realize that I haven't confronted my W on the OM since she left... but that could very well change this weekend when she comes back to pack up the rest of her stuff... But I don't want to hijack your thread with my sitch...
Listen, I don't want to sound too harsh here. You're doing a great job so far, and you're absolutely doing the right thing by taking your thoughts to this board to get the advice of some serious vets. I just wanted to chime in and preach a little patience.
DON'T push for a D until you're sure that you're completely comfortable with her accepting that and it being the end.
I don't think you're there yet. And that's fine. Neither am I.
Remember that time is on your side here. Even if she files on her own, you've got plenty of time to gather your thoughts, contact your lawyer, and figure out what you really want to do. Let HER do all the legwork, unless you've decided that you're fine with ending your M right now.
Stay Strong. Remember to BE PATIENT.
And for God's sake, pay attention to the advice these awesome Vets are giving you! You don't have to follow everything they say, but it behooves you to toss around their ideas in your head for a few days at least.