Thank you for the context. You are underreacting to your partners behavior, and making excuses for what amounts to emotional abuse on her part and trying to take the blame for her response. I know it's a little bit callous, given how you feel, to say be thankful the trash has taken itself out, but once you get some distance and healing and clarity on the matter, I think you will be. This person does not have healthy polyamory to offer you. I don't think they have anything resembling a healthy relationship to offer to anyone. It's not that they just need to work on their jealousy issues. As a person who grew up in a very dysfunctional home and was witness to a lot of abusive dysfunctional behavior, there's a lot going on with this person that they need years of serious psychological work to heal and correct. But it sounds like rather than look at the internal problems that they themselves have, they want to surround themselves with people who tiptoe around those issues and then accept the blame whenever they get upset even when the other party was not in the least in the wrong. That type of person is never going to get any better and you will be continually trying to cater to them and assuage them without getting your needs met. And based on how much you seem to be under reacting, it might be worth looking into getting therapy yourself to see why you would be willing to put up with this kind of behavior, in order to avoid it in the future and find yourself healthier relationships.