I'm sorry that things are so hard with C. That's so sad.
Here's my opinion, though. I've been following & enjoying your blog here for a while. Whenever you mention MrBrown, I think, "Ah, the fun one! Great!" And whenever you mention C, I think, "Oh, the difficult one. He sounds like such a drag." I admire your life very much, and I have thought many times how I would love to have a husband like Ren and a man like MrBrown--but I have never thought, "Wow, I want a man like C."
I know you love C. But it seems like everything with him has been such a struggle for such a long time. He didn't like hearing about MrBrown or other men, etc. He wants to be poly yet the only other woman he gets involved with is adamantly mono. He keeps breaking things off with her, then getting back with her, then breaking his fluid bond with you without telling you, etc. He seems to be indecisive and to struggle with basic communication.
You have done a remarkable job of "owning" your feelings and treating your anxiety about C as if it were your problem to deal with. I didn't want to say anything because you were doing such good inner work--but I kept wanting to say, "It really sounds like your constant anxiety about C is not about your own issues with anxiety--it's a problem with C himself."
You link your need for reassurance to an addiction, something about your own brain chemistry--yet the only aspect of your life in which you are suffering from this particular "addiction" is with C.
Sometimes I think there is a danger with being too good at owning one's feelings. Sure, you want to process your own feelings and deal with your own issues without blaming someone else--but what if someone else really is the problem?
Not that C is a "problem," I just mean that your issues with him stem from his inability to decide what he wants, inability to communicate what he wants, and inability to make you feel loved and cherished.
He seems like the kind of person who wants other people to decide for him. His ex isn't comfortable with you--so you don't meet her. That was her decision, not his. Molly isn't comfortable with you, so he's wishy-washy about being involved with her. He won't make a decision.
Now, I am really biased in my opinions because whenever I hear that someone has ED, I am immediately reminded of my ex and cannot get the comparison out of my head. My ex had sexual problems which seemed to be linked to his inability to know what he wanted, express what he wanted, or ask for what he wanted. (This led him to quietly resent me for years, which is not the case with C; yet still I feel they have similar traits).
So, maybe I'm wrong here. But I, personally, sympathize with you losing respect for C.
(And if he's got a woman who very much wants to be mono with him for the rest of her life in spite of the fact that he has ED...well, let her be happy with him, then!)
Single, straight, female, solo, non-monogamous.