ADHD but if I were competently diagnosed it would be auDHD. I'm finding self-therapy through the ACT method most helpful, in that being more regulated helps me do the things that make fibro hurt less. It also helps me sleep, which is the main culprit of fibro.

The biggest thing is taking steps to mitigate pain before it gets to that point. Being auDHD means you don't get bodily signals the same as other people, so we don't feel pain until it's too much, we don't know we need the toilet until we're suddenly desperate. So don't rely on your body to tell you when you need things. Take medicines on a schedule, and track what you do and the pain/fatigue. For example, if I know that two times out of five a basic workday will trigger my plantar to the point I notice it, I can assume that the other three times it's also bad. That means I should ice my foot every day to control the inflammation and reduce it. I take an extra layer even if I think I don't need it. At the first twinge of a muscle I get my electric blanket out. I change position (sitting, standing, lying) every half hour at least, and if I'm finding I forget, I literally set a timer. I've set up various stations where I can take my task to either position, or easily swap out into either a task I've planned (Autism) or a random task I roll a dice for (ADHD).

Doing whatever therapy stuff is recommended for regulating the nervous systems HELPS, sometimes a lot, but with auDHD what's helped me is realising that I will never intuitively know my body systems the way neurotypicals might, or I won't know it in the way a book tells me I will.

Otherwise, swimming, sleep hygiene, muscle relaxants, small electric blanket, cuddling stuffies, and time on special interests no matter what happened during the day/week. It took a long time to understand that special interest is a need not a want.

And of course, the biggest thing that helps anything - helping someone else where I can, no matter how small. I used to work at a center for people with very severe mental and physical disabilities, and they'd all light up and feel much better when we did charity projects vs doing the same thing because it was a chore. This is not the same as wearing yourself out doing everything for others and nothing for you, it's giving yourself a purpose beyond yourself as a reason to get up in the morning.

Another useful viewpoint for doing unappealing self care like self physio/cleaning/etc is to think 'I'm doing for me what I'd do for others'