Lost, there are a lot of details that are missing here. Like how was the marriage prior to BD? Is this her first A, whether EA or PA? Any other details that will help?
So I agree with overrnbw. Most of these things are caused by a lack of respect. Leaving your MBR is not commanding respect. "You are cheating, therefore you are NOT welcome in our MBR until your A is over." She can live downstairs and use the full bath down there.
You mention she is an exec at a small company. What do you do? Are you as successful as she is? If not, that too can play into the lack of respect.
She is holding on to you as plan B, while solidifying her plan A. How does that make you feel? Doesn't that make you want to take your respect back?
She is trying to hold onto you as her H, while using her AP as her lover and emotional support. This shows a lack of respect for you.
No respect = no attraction. If you want to attract her back, then you need to take back your respect. You start by respecting yourself!
GAL. 180. detach. Do not agree to a demilitarized zone for the next 3-4 years to placate her for your son's sake. That is no way to live. However, I sense impatience on your part. These things are marathons, not sprints. Give time for the process to work. I see you trying use the "detachment" and "NC" won't work. First NC is not something you demand. It is what you do. You don't initiate contact. You respond, in your own time, to her questions with as few words as possible. Yes or no questions mean respond with yes or no. Contact that is informational requires no response. I don't care how independent and strong she is, when you pull back she will wonder why. In fact, it works better for those types since they tend to be controlling and detachment and NC will make her feel like control is slipping away.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018