@RockinHorseShit, so sorry you have been through the wringer with it all too. I was diagnosed in my 40s. I was under neurology for well over a decade and told I had every thing from MS, to Lupus, to epilepsy, before they finally said ‘it’s probably CFS and Fibro, but we don’t do those’ and then left to fend for myself. 
[anger]. My GP at the time told me it was anxiety and I just needed to go for a walk in the fresh air! 
When I went to the GP and suggested I may have PoTS, first response was ‘what’s that’ then ‘oh, well you couldn’t possibly have that, it’s extremely rare’. I insisted on a stand test, which they did very badly, but thankfully still showed I clearly met the criteria. They then agreed to do a private referral for me and I was diagnosed first via a properly executed active stand, then a TTT.
I’m now having fun with the menopause badly affecting my PoTS. Incidentally, I was also told I would be miraculously cured by the menopause, whereas my new specialist admitted they don’t know what will happen, because no studies have been done on menopausal women who have PoTS and the earliest diagnosed cases from the 90s are only just starting to go through the menopause now. They also said they are seeing a few cases like mine, where the PoTS goes haywire throughout perimenopause though.
My son was seen twice by Community Paeds in infant and junior school, but left with no clear diagnosis. At 13, despite multiple atraumatic dislocations, the paediatric Rheumatologist wouldn’t even diagnose JHS’, but thankfully other doctors in the same hospital disagreed and diagnosed HSD under the new criteria. He was referred to adult Rheumatology by his PoTS specialist when he turned 16 and they easily diagnosed hEDS based on the 2017 criteria. I haven’t bothered getting a diagnosis for myself, as I doubt it will benefit me treatment wise. If my younger dc’s hypermobility gets bad enough for a diagnosis they already have ds as a first degree relative, although my dm was diagnosed when ds was first assessed, but they were not interested in a clear family history. My PoTs specialist is nagging me to accept a Rheumatology referral, but it would be a historic diagnosis at this point, as my joints are now painful and stiff and I can’t face another battle if it isn’t going to benefit me treatment wise.