"I've either gotta "run away" as you put it to break the dependency I have on her for my happiness and risk becoming a faint memory in her mind, or stay and be her friend and possibly have some happiness while risking torture from OM getting all the real closeness with her. And either way I go, there are no guarantees...she might still end up with OM."
You're reading this stuff all wrong. I think the others sense how deeply embedded you are to your sitch and so are recommending to "go dark". Maybe you just need to "go dim" limited contact, but still getting a life.
I see that is where the issue is. You haven't been getting a life. You need it to break the dependency, not just going dark. If you never had married her, what is it that you would be doing? What is it that you've always wanted to do? Now's your chance to do it. Get your mind on something other than your M.
Get a hobby, exercise, anything. One thing I started getting into was meditation. It was great to quiet the conflict that was going on in my head when all this was going on.
Stand on your own two feet and become "the man". You need to get your confidence back. Not for her. But for you. Once you do, she'll notice. But you can't let that be the reason why you're doing it. If all you do is do things to see if she'll come back, you'll fail because it's not really in your heart to do it.
What are some goals that YOU want to achieve that are not M related?
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.