OK, so you are respecting your H's new R, which is appropriate and appears to be what he wants.
I understand that you feel like the OW. I am curious though as to what behaviour was not healthy when you attempted to re-engage? Are you saying an attraction by both of you?
If you are going N/C, there are a few things to understand:
+ N/C is FOR YOU, first and foremost, to help you detach. + a side effect MIGHT be that your absence might stir your H to miss you. + N/C is generally temporary, unless you are setting it as a boundary regarding your H's R with OW. If that is the case, then I recommend you read up about AtLRT in DR, because that is the stance you are taking if this is about the OW. + N/C is about not contacting your H. In a strict sense, it means not responding to your H, either. Although modified, it might mean you respond to SOME contact from your H and not ALL contact.
I do want to frame the context of your sitch: + you left your H and M + your H is likely to have serious trust issues now, around you, due to feelings of abandonment + your H has now become involved with OW (one would assume it is because he is moving on)
Consider this...
Your H DOES NOT TRUST YOU and HAS CHOSEN A OW.
Do you really think that telling him he can't be in YOUR life while he is with OW is going to matter, to him?
I believe that it is really important for you to ignore the OW, right now. Whether you chose out first... he still is your H... and unless the two of you are D... SHE IS the OW.
How can you show him that he can trust you?
How can you show him that you are a great choice for him?
How can you show him that life with you NOW AND INTO THE FUTURE... will be much better for him and something he might desire?
How can you be attractive to him?
You do still sound like you are sitting on the fence...
If you want him back...
Then work on that. That's your goal...
Use the above questions and the DR book as your guide to help you work out what might help you achieve your goal.
