I'm so glad you could afford to pay for the tests you needed OP. It's a terrible state of affairs when you are left deteriorating for want of a simple blood test.
In my case my son was referred to a paediatrician due to mouth ulcers, nausea/stomach & bowel pain and raised platelets levels, low weight etc etc.
The paediatrician refused to any tests (I now know a simple stoole calprotectin test would have got us a long way - showing inflammation). They said his symptoms were "non specific" despite me saying exactly what my concerns were - which my concerns turned out to be the case. Asked to come back in 3 months (for another chat no doubt). I was told "he can't just go referring everybody". GP said they "see people with gastro problems every day". That left me wondering- surely there is a well trodden protocol to help them then?
No further help or tests from my GP despite phoning them and crying while asking how low my son's weight has to get before he is at risk of cardiac arrest/death.
2 visits to A&E later and he was referred for appropriate tests by gastroenterologist at the hospital with heads up that he expected a diagnosis of Chron's or Ulcerative colitis.
My son now has a diagnosis of Chron's and his symptoms are well managed with treatment.
We are asked to use GPs etc and stay away from A&E as a GPs visit is a fraction of the cost but it's impossible if they can't/won't refer for the tests that are needed.
These medical staff are on big wages (GP/paediatrician) but can't order simple tests so you go round the merry go round of seeing them time and again wasting far more money than the simple tests needed for diagnosis would cost.
I hope you get the help you need quickly OP and your symptoms reverse.
I think we should move from a model of GPs to treatment centres where the primary focus for an unwell person is "What tests/help do you need - right now". It felt to me like the GP/Paediatrician was on a performance target for getting people to clear off without any help or a referral. The less they do the better they seem to feel they have performed because the person has gone away without costing the NHS any money. Except they will be back time and time again and then present at A&E.
I apologise for the rant. I think I have PTSD from seeing my son so ill.