Oh dear, hope hurt & damage stays limited and fairly reparable … 
I’m still not too sure about the term 'flare’. 
It means that “the flame” is quite a bit more than usual. So relative. In comparison. But compared to what?..
Inspired by your tornadoes, I think a (bush) fire 
may be a more helpful image for the continual aspect. Also because home fires (furnace, oven etc.) are made to be well controllable. The fibromyalgia is any burnable substance, let’s say dry wood now. The subduing is the firefighters 
. Now in most of us the fire is kindled when it was first set off and at least glimmering or burning a bit all the time. Pain killers and sleep meds etc. are the chemicals used by firefighters to dampen the fire, which may be quicker to suppress symptoms, but have quite some side effects. All other treatments (psychological; physiotherapy; diets; changing the surroundings; supps & herbs) can sometimes work in that way too, if they don’t fit, but it happens less and isn’t meant to happen. They are trying to be like the firefighters removing the dry wood (triggers, e.g. diets, surroundings), quenching flames with water (physio, supps & herbs) or by removing air (psychological, physio, supps & herbs).
Back to flares: In a few rare cases, the fire is quenched, no more or only occasional flares which wdnt really be seen as such. Some have a bit of fire, don’t have to do much to keep it under control, can have more flares. Some have a lot of fire, under control or no, flares the less they have it under control. Etc.
I’d say I have “a lot of fire”, but use everything apart from chemicals (because these increase the fire) every second of the day and night, so I have quite a lot of and very slowly increasing control over the fire and over additional flares and can lead a happy life, altho a lot of it is “consumed” (like the pun? 
) by keeping it controlled. That makes it not nec look like a ‘continual flare’, only like a small fire - not like the ones at home, but a bush fire that can break out fully anytime, but may not be left alone for one second. However if I now stopped treating it that intensely, it would fully consume me. Continuing the ‘consuming’ image: one part of my life is consumed by the symptoms, a 2nd by getting them more under control, thru which a 3rd is “feeling well”. Not sure - let’s say 40 / 30 / 30%.
But back to the flare in comparison to the fire: When I have worse hours or days or weeks than usual that is a flare relative to the “normal” fire, agreed. If we compare ourselves to the years before fibro, then a fire is praps the right word. In my case a blazing fire. And I’ve just now realized the reason why I started calling this a continual flare: Because since Dec19 it was a continual blaze and I never had any good days, so I cdnt discern flare from not flare, like others could.
Due to the treatments I've been slowly getting the blaze more under control...details:
A few good days in the summer of 20, after starting cryotherapy. But a break from that due to clinic Sep20 and harmful physio-treatments there brought me back to the old blaze. Nov & Dec20 I started work, and newly starting acupressure managed to keep all days OK-ish, meaning pretty bad, but not totally bad. Jan21 was good without work, Feb21 first good with a lot of digital work, then I “broke down” for a month March to April, the treatments cdnt get the blaze under control, or actually flared it up more. After that slow baby steps.
No need to blame your answer on the 
because ‘flare’ meant for you what is visible, and I think many people think of it like that, so it’s a welcome point of view to grapple with. 
Writing a book?: Well for me my blog & references are book enough for me. I am actually already writing a lot all of the place, in forums and otherwise, about the fact that I think there is hardly any difference between male and female fibro, how I got to my diagnosis, that I was very lucky that my friends were helpful in helping me much better than docs at finding good treatments and that my wife is … usually … very supportive and the treatments that help me. The thing why I don’t think a whole book would be helpful for other people is that I have various unique symptoms and treatments, that don’t seem to help others, or they are simply not prepared to, so I feel a bit alone, walking my own path and hoping that people can glean a little bit out of what I write: My answers to their specific problems, my blog showing my path, my cause, symptom and treatment lists. I would also wanting to continually update what I write, like I do on the web. I know some people like reading books, but at the moment I don’t think I’m the right person to write one. But thanks for the kudos 