Hi Karen, I am in similar sitch as you. I keep everything. I document everything. I note conversations. Not sure if I will ever use any of the papaers in my big file, but it has uncovered lies that I may not of picked up on otherwise.
Respond to him with only what requires responding to. He is using up all your energy. Dont buy into his dramas. I would do only what is agreed to and what make slife a little easier for kids.