As said before, it's about them, not you. Yes, you will be affected by it, but they are adults and will do what they have/need/want to. Being happy sometimes takes a long time to figure out. You don't have to pick sides, and you don't have to be the peacemaker, either.

As for being trapped, well you can go out for a walk, or to a cafe, or just be alone. Go into the discussions with an open and listening mind, but if you are angry, that's okay, too. Take your time, it will be alright.