Quebec01, I have fibro, and am now on disability because of it and mental illness. I am trying to learn to focus on what I can do and ignore what I can't. If I didn't, then I would keep the Kleenex company in business with all my crying.
I am sorry your relatives don't understand. (Too bad we can't pick them, but just get "stuck" with them!)
I encourage you to see if there are other folks around you who can be supportive. Is there a fibro support group near where you live? My BFF also has fibro, so I have a special person--as well as the folks here, such as sabby,---who understands.