Welcome to our community, Joshua. Are you familiar with the Divorce Busting principals? Have you read Divorce Remedy? If not, please get the book ASAP.
It is good that you sought help for your possessive ways. Have you been able to identify the root cause for this problem? How long have you been in counseling?
I know it would be a huge problem in my M if my H started the actions you have described. Can you see how it damages your R? Are you possessive in other ways or other people?
Until you are able to fix yourself, it will be extremely hard to repair the M. You see, in DBing, there is a lot of backing off, turning loose, setting free........and how can you do that if you can't get through the day without drilling her about what she's doing, where she's going, who she has seen or talked to, etc.
You are smothering her, and that is the last thing you want to do to a WAW. It is good you have not pleaded or begged. Now if you will show her you do not need to control her life and can be confident enough that you don't have to check in with her to assure your own doubts......that will be a major step forward.
Another thing you can't do with a WAW is to talk her into changing her mind. B/c the more you talk to her about it.....the more you are enforcing her decision to leave. She doesn't put much stock into what you say anymore, but she watches your action.
Another reason for reading the book is b/c you may not apply the correct moves to your particular stitch by just reading the forum only. For instance the NC you mentioned. This doesn't work very well when living under the same roof. However, not initiating contacts throughout the day is applicable for you. In other words, wait for her to contact you by calls, texting, emails, etc. When at home, give her space and don't smother her with your questions.
About staying in a motel for a few days to see if she misses you......I really don't think it would accomplish anything. Giving her breathing space is what she needs, not you going away for a couple of days, then return back to the same old stuff.
Do you recognize what triggered you into this possessive behavior?
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!