I would go point for point again. But I think the first thing that needs to happen is you need to feel safe to bring up and discuss points without feeling scared of a fight. Thats not a great way to live within a relationship.
Never live in miserable silence. You have to figure out how to talk to them about your needs and desires and not be afraid of a fight. Sorry scratch that, they have to learn how not to panic and fight with you everytime something is brought up that causes them discomfort. Thats not way to live within a relationship. Nothing will work long term if all 3 sides can't talk.
I mention writing a letter, because it gives the other side time to think and re-read, and you time to be clear. By removing the visual queues sometimes the factual context of the letter will sink in better. I am not sure what you have tried or havent tried. But you have a right to feel what you feel and want what you want.
and yes, I know as I write this I make it sound like puppies and rainbows and life will be easy. It isn't, poly is hard work, it isn't as simple as just two people. There are other feelings involved now making in far more complex.