This sort of thing is rare. What we really need to be asking ourselves is, why women are less likely to be believed by doctors, and why women are more commonly dismissed by the NHS. Why it's mainly women with real medical conditions who spend years and years trying to get diagnosed, constantly accused of making things up. And then they finally get diagnosed years later but nobody ever apologises for having accused them of lying. There are mothers of genuinely ill children who've been threatened with social services, threatened to have their child taken away from them, only to have their child finally diagnosed a few years later, proved with blood tests and scans, and yet they never receive an apology, and still get labelled as "an anxious mother" even after their child is officially diagnosed.
Not all of these are even rare medical conditions. Even PCOS, which is more common than doctors would like to have us believe, typically takes, what, seven years or something to be diagnosed? And all that time, women are accused of overexaggerating, accused of attention seeking, being told it's just normal period pain etc. Even though a lot of them end up having operations in the end.
Ehlers-Danlos is very often co-morbid with POTS and other things. This is a noted fact. And there's thirteen different types of Ehlers-Danlos, so even if someone has different symptoms from you, it doesn't mean they're making it up, it means they have a different type.
It's also widely noted that autoimmune conditions in general tend to be co-morbid. So once you have one autoimmune condition, you're more likely to get another one. And yet women people are accused of making it up, being told they can't possibly have all those illnesses together.
There are endless stories of people with rare or widely-underdiagnosed conditions who spend years and years begging doctors for help, years being ignored and accused of all sorts. Many of these women people end up spending a lot of money on private healthcare, even getting into debt, because the NHS won't listen or doesn't treat people holistically.
And a lot of "rare" medical conditions aren't nearly as rare as we think, just rarely diagnosed because people with those conditions are so often ignored or turned away.