Thanks to everyone who has responded to my original post. I appreciate your thoughts on my situation, and your advice about what to do now.
AutumnalTone, what you said about my relationship with Craig makes a lot of sense to me. I too was feeling that I should take some space to be on my own, and only be around him when I am capable of being a somewhat normal girlfriend to him, rather than being mopey, angry or bitter. When things were just tense with me and Ted, I tried to limit my time with Craig in such a way as to allow me to be as pleasant around him as possible. When things started to get really bad with Ted, I took Craig up on his repeated offers to "be there" for me, even though I knew at the time it was probably not the best thing to do. It was helping me to get through a really stressful time. I've let Craig know that after his current visit to me ends early next week, I'll want to spend some amount of time apart, but that I will stay in touch with him, and I'm not ending the relationship. He took it fairly well, and was generally understanding, though he seemed a bit disappointed.
snowmelt - thanks for your comments, too. The angle of incompatibility is interesting. I'm wondering in what specific ways you mean, whether you mean just mono/poly or general desires for relationships, or other issues. Ted and I were compatible in some ways, and incompatible in others. I feel every couple has areas of incompatibility, however. If these get in the way of what the couple wants to do together, then its a problem. I was willing to accept my incompatibilities with Ted in some areas because we were able to live mostly harmoniously, and in addition to sexual compatibility, we shared common beliefs that shaped our shared lifestyle and future plans. These common beliefs were and are important to me, and they are the areas where my relationship with Craig is particularly challenging. He's offering to try to change his lifestyle for me, but I feel if his underlying beliefs don't change, it's not right for him to change his lifestyle.
Your point about Ted never being poly at heart may be true. I know that my polyness hurt him more deeply than he let on, but I only found this out more recently. I was willing to suppress it and stay in a monogamous relationship with him for years because to me, our relationship was more important than being able to act on my poly tendencies. I know I am not the only poly person who has done this or for whom this was true. He was aware that I was sacrificing that to be with him, and claimed the most recent time I brought it up that he was no longer comfortable with me sacrificing that part of myself. But perhaps it was some subconscious desire on his part to bring an end to our relationship. I'm not sure. That's not how it was presented.
As far as knowing what I want, I think that has been pretty clear to me in terms of configuration. I was content with a primary partner, and additional friends/lovers for myself, though I am not sure that that's what I want in future. I had hoped that my primary would have been on the same page in terms of other relationships, but I know that the level of relationships / depth of feelings can't be controlled. Given that, if I get into a similar model in the future, I would want better agreements in place as to what the desired trajectory is and what we will do in various scenarios. Ted wasn't willing to work through that with me; he claimed that there were too many unknowns and situations that could not be foreseen, and that we should just play it by ear. I was uncomfortable with that, but agreed to go along with that since he refused to do otherwise.
archbishop69, thanks for your advice on centering myself. I appreciate that. I'm not sure if there's any chance of Ted returning. His friends and family have been pretty critical of his actions in this situation, and have expressed to me and likely to him that they feel he's making a mistake and being very rash. But he has decided that he's going to go with his emotions for a change (he's always been very rational - INTJ), and this other relationship with Deirdre is apparently what his heart wants. He told me he still loved me, even up to the end, but that Deirdre forced his hand. I don't know how true that is; maybe he's just trying to let me down easy. In any case, if his relationship with Deirdre (which is currently monogamous) ends, I don't know if he would try to come back to me. He doesn't seem like the type. I was hoping he and I could at least have a friendship, but he claimed that we were "never friends" and that it would be hard for him to spend any time with me because Deirdre hates me. So...yeah. If he ever wanted to be in my life again, there would be a lot of heavy conversations and trial runs and etc. I don't know honestly if I could ever trust him to be my primary again.
GalaGirl - Thanks for the advice and comments, too. I'll try to respond to your different points.
As far as figuring out and expressing wants, needs and limits, I agree that this would have helped, and is helping now in my relationship with Craig, though my wants/needs/limits are changing from what they were pre-breakup of my marriage.
I had wanted to make more explicit agreements about these things with Ted when we started exploring polyamory together, but he was pretty against that, as I mentioned above. Because the polyness was new to me, I was still trying to figure out some of those things, and it's not easy for me to figure things like this out hypothetically; unfortunately, I'm the kind of person who needs to be in a situation to know how I'll respond or what I will feel or need.
Craig hasn't said that he needs to know by a certain time. He's been very patient with me. That's one of his good qualities. The flipside of that is that he's kind of passive and perhaps too accepting of bad behavior on the part of his partners (Barbara's in the past and mine, currently).
I struggle with the whole bag idea. What belongs to your own bag vs. what is in that of others? Is there something that is not in anyone's bag, but sort of hangs between / outside? I hear a lot of "be responsible for your own feelings" etc. but it seems like this is sometimes abused in the sense of, "Well, if you have any negative feelings about something I did, that's your problem." Any thoughts on that, or recommended reading?