I'm sorry to hear that. Hopefully it's just a point you both needed to get to, and now she has the time she needs to compute and analyse, she will realise that you were trying to deal with the new reality, but that you had some backward steps as well as forward ones. After all you were instrumental in articulating it the poly situation in the first place.
I fear I'm going down the same path, another bad night tonight - just when it seemed like we were making progress, she was out with her friends and I started to obsess and create scenarios in my mind, that actually weren't true. We spoke tonight and she said I'm losing her. If I cannot keep a handle on this soon, I know I will. because I know the worst thing in all of this situation, is my bad reaction to things. I will qualify this and say that some of my reactions have been perfectly understandable. But I know that some have been borne out of complete obsession.
Thanks for the info on therapy. I fear I might need grief therapy soon!