Sounds like you are having a bit of a rough time and for it to have been going on this long I think is truly unacceptable!
I have only had one private medical experience that was paid for by the NHS and I did and still do think it was worth it. In as short a version as I can give here is my experience, I injured my ankle falling from a height and landing on the side heard a huge pop and honestly thought my leg was going to be hanging off the side before I took a look. It wasn’t, there was no visual difference but I could not walk.
Very quickly it doubled in size so went to A&E and had an x-ray. I was told it wasn’t broken so must have just been a sprain so to basically ‘walk it off’ although I was given crutches (I think mainly because I stood my ground that I was in a LOT of pain).
I ended up going to my GP because it wasn’t getting any better, swelling was still huge and a huge amount of bruising coming out. I was sent for a second x-ray, nothing found there either so referred to physio (this is probably 2-4 weeks after injury occurred).
I had nearly 2 months of physio and nothing helped, I lost, I would say 70% of movement in my ankle so I was referred for an MRI.
The results for the NHS MRI can back pretty quick but were “inconclusive” this is when I was referred to a private hospital.
When I met with the private consultant he took one look at my NHS MRI and straight away said the reason it is “inconclusive” is because it was blury (blaming NHS MRI not me moving), consultant said he could not see anything so I would have to have another MRI at the private hospital.
I did, again super quick and follow up appointment a week or so after. I had teared ligaments in my ankle, I had a load of scar tissue build up and my body had GROWN (eurgh) an extra ligament to support the ankle. Basically my ankle had been left unsupported for so long I managed to grow a ligament (consultant said he has never actually seen this but heard of it happening). Obviously I had to have an operation to sort this all out. 2 months I waited for an NHS paid, private operation and within a month I was almost back to normal.
I probably have around 70-80% depending on the day range of movement back. I wasted so long with all the ‘protocol’ the NHS has to go through, I was told if I had been given the proper treatment from day 1 at A&E I might not have had to have the operation and my range of movement would of definitely been better thus now 2/3 years on it wouldn’t be causing me pain. I am probably going to have a bad ankle for the rest of my life!
I wouldn’t wait for the NHS to finish all their tests, if you can afford to do it, do it.