I wouldn't look at it as H "choosing you or OW". It's more "is H's affair over now, or will it be over later?" If it's not over now, then it will be over later.

He can "choose you" and secretly prolong the affair, or he can "choose OW" and have the affair end later and come back to you.

You should act the same regardless of when it ends, continue to work on YOU, continue to 180, continue to GAL, continue to "act as if". Learn to validate yourself and self-soothe. What H does or doesn't do is only as significant as you build it up to be.

If you build this "choice" into a huge event, it's going to have a big emotional impact on you either way that you may have a hard time managing. Relax and breathe. Operate from the perspective that there is no near-term event to worry about, and your timeline of interest is 2-3 months, not 2-3 weeks.

Accuray

Married 18, Together 20, Now Divorced
M: 48, W: 50, D: 18, S: 16, D: 12
Bomb Dropped (EA, D): 7/13/11
Start Reconcile: 8/15/11
Bomb Dropped (EA, D): 5/1/2014 (Divorced)
In a New Relationship: 3/2015