Oh my gosh, my family is going through the process of getting court ordered at the moment and I am dreading all this… my ex- is also very controlling, stubborn, unrelenting, etc.
Sorry I don’t really have advice, but I feel your pain.
I would just say next time he asks you to agree to something, just don’t give an inch unless the reciprocation is also settled. It sounds like normal relaxed cooperative behaviour probably won’t work.