Is it possible to test the waters by setting some specific boundaries without telling them everything, and see how that goes? If I had told my mom I wanted a break from having to do a particular family get together because it caused a flare up of my MI, it might have slowed her roll, but it would not have stopped her. What stopped her was my being firm and sticking with it. She still gives it a go every couple of years. But I will not be worn down by it anymore. My mental health comes first, so I just keep that in mind. It has not affected our relationship negatively at all.

This is only if you have not already tried that approach. If you have, nevermind. I wish you well with this. It's not easy.