I attach an annotated shot of your MRI. The left shot has something that I haven’t noticed before, is it a vessel or what, I don’t know. In the right shot, the ‘sagittal’ one, I’ve seen the abnormal features of your MRI before, most of them are shown in Dr Diana’s ‘The Driscoll Theory’ and are fairly common amongst those who suffer similar symptoms to yourself and post on this website.
Basically there’s excess CSF fluid in your skull. It could be caused by your low-lying cerebellar tonsils acting as a ‘bung’. Warning – do not let them do a lumbar puncture to check this, as this can make things much worse and give a false-negative result. If they want to check it, tell them to use a non-invasive method (they do exist!) Many of us are on Diamox to reduce the pressure this extra CSF exerts on the soft tissues. It compresses other structures, like the pituitary, leading to reduced function, or malfunction.
We can all empathise with your suffering and can share what we have found helps. I have the aching body, where the pain get’s worse the longer I stand too, so basically your body’s telling you not to remain standing too long.
I have had to find easier ways of doing my daily tasks, some people refer to it as ‘working smarter’. I have several other posts you might find useful if I get time I’ll sort out the links, if not just do a search on any terms in search box above.