Well, it's been a week and many changes.
My wife finally realized that forcing this relationship was not in the best long term interests of our relationship. She then told me she was ending the relationship with "R" and that she would own the decision. At first I was relieved but then I became reflective. I then chose to go to her and change the dynamic. I told her I wanted to give her the opportunity to see where things might go with "R" and that I was choosing this freely. Since it wasn't being forced on me, I could feel my love returning, replacing the resentment and from there I was able to offer it as a gift. This little thing completely changed everything. I no longer felt I was drowning, I felt empowered and back in the relationship. The change in my wife was dramatic as well - she saw the almost immediate difference in me and she also felt the love flood back. It was a very powerful moment for each of us.
I did request that she have "R" read this
and realize that this is where I would like for him to be coming from rather than some of the earlier items. My wife agreed with the statements in the link and said if he can't be like that, then she shouldn't be in a relationship with him. This alleviated my fears of "R" since I could accept him acting like my partner in this and my wife agreed that he needs to act like a partner. He should either respect me and our relationship or she didn't want him as my metamour. Like I said, major changes in attitude from that tiny difference in perspective.
The level of stress and anxiety I've had over the last several months is now almost gone. I know we still have a long journey and there are many more potential bumps ahead but I truly feel we found the win/win for us. I feel like we reestablished our partnership connection and that hopefully gives us the strength to handle the bumps better. I certainly feel more confidant than I have in a long time.
My observation that I can give back to the poly community is that one partner trying to steamroll a mono relationship to poly isn't the best approach. It creates levels of resentment that impedes acceptance and sets up a win/lose dynamic. Instead, present your case to your partner so that they see the level of importance it is to you but don't force the decision or take the decision away from your partner. Trust them that they love you and will eventually be ready to work towards a win/win. It's out there if you pursue it together. My two cents
Thanks again to everyone who contributed and gave advice. I truly read and contemplated them all.