The fact that long covid sufferers, and migraine sufferers, and fibromyalgia sufferers, and chronic lyme disease sufferers all tend to be affluent women is not because those are the people who "really" have those diseases, it is because those are the people who lie in bed due to ennui or post partum depression, feel sorta achy and have a headache as a result, and search for a diagnosis. I'm not going to speculate on the source of your fibro, and I definitely think Corpse is lying about his, but the fact that most sufferers are middle age women is because most sufferers are psychosomatic and this particular brand of delusion lends itself to people who have little to do and time and money to lie around, become depressed, slip into a state of ennui exasperated often by alcohol and drug use (particularly opiates they take for the "pain".)
That isn't to say there aren't people who suffer genuine physical chronic pain, but unfortunately their diagnosis has become all that much harder due to all of the psychosomatic sufferers.
Corpse is neither. Corpse is almost certainly a guy with a normal, unremarkably deep voice who lowered the pitch a bit and talked in a croaky vocal fry voice to read creepy anecdotes he found online. Then he branched out and decided to keep doing the voice in social situations, and found the need for a story about it. He came up with the gastric thing because it covered his bases for when people realized he didn't always sound like that. He likely told the many relatives who know him IRL and followed him online that it a tactic to stay anonymous. Then he realized how helpful all the sympathy he got from his "illness" was in building his fangirl base, so he started cynically adding on other vague illnesses. Doubly helpful that those other illnesses are the type that fangirls will defend because people like Lady Gaga and I'm sure other female icons have diagnosed themselves with.
So tldr; corpse is definitely lying but the ties bonding all of the women who have the same thing are that they depressed and have the means to wallow in it, not that they are the people who "really" get fibro.
Hey, that could def be it. I'm not a middle aged woman so I have zero clue about what can be part of it, all I know is that it's seemingly random (I will say tho, there are no ties to economic status) and depression can be comorbid to fibromyalgia (along with anxiety, but that's also why it's exclusionary, because chronic pain can come with depression without being fibromyalgia)
To help sort it out, I'll try to describe fibromyalgia itself better than Corpse did or w/e - to be diagnosed, you have to cross off every single other possibility, but a diagnosis of fibromyalgia isn't just one disease, it's more like a pattern of multiple diseases popping up at the same time (think of the term as more of an umbrella). It usually includes chronic pain (on both sides of the body as well as above and below the waist), chronic fatigue (usually insomnia as well), IBS (Irritable Bowl Syndrome), exercise aversion, "fibro fog" (brain fog, difficulty concentrating and difficulty with memory), however a vitamin D deficiency (over 90% of ppl with fibro have one myself included), depression, and anxiety are comorbid (you don't need them to be diagnosed, but they're common).
It has to be going on for at least 6 months repetitively, I would assume a blood test for fibro is now required, and the vast majority of *recorded* sufferers are women (however, men have been shown to be chronically misdiagnosed with Bipolar disorder or Bipolar Personality Disorder because a lot of doctors think they can't have it specifically because they're men)
There's also a test doctors perform when you're being diagnosed, which is checking 21 pressure points on your body, which seem to appear exclusively in those suffering from fibromyalgia (so if you don't have it, you won't feel pain in those areas) and there is a margin of error of 2. The doctor basically goes to a part of your body (let's say the right forearm) and they'll press gently on two spots on your arm and ask you if one or two hurts more. These also need to appear on both sides of the body as well as above and below the waist.
I should also say, the evidence right now points to it being a chronic malfunction of the nervous system, not psychosocial or psychological at all. Your nervous system misinterprets pain signals from your brain and makes pain appear when it isn't there, or amplifys it.