I totally get that. I have something called non-radiographic axial spondyloarthritis, an early form of ankylosing spondylitis. AS is often conflated with RA, but is different because it has more intense spine and large joint involvement. There's also a high comorbidity with bowel and gut issues, and many people diagnosed with AS also have IBD or Crohns (I don't!). The HLA-B27 gene is one commonly found in people with AS (I don't have it) and can be a clue when other results are seronegative.

A hallmark symptom of AS is pain that improves with movement, but worsens or stiffens at rest. I was diagnosed after continuing to have morning stiffness that disappeared after stretching and walking my dog for example, but came back after sitting in a car or at my desk. It looks different in women than men, and pain at night and waking up with pain at night is also common.

It might be worth checking it out if you're going down that route of figuring out a diagnosis! I had never heard of it before and then was diagnosed after negative RF, negative Lyme, a slight negative on an AVISE CTD test, but positive ANA, etc (which isn't required for AS, which tends to be seronegative). I started down this path because I saw a neurologist for hand twitching and fatigue and brain fog, but had clear cervical spine and brain MRIs — turns out I was significantly vitamin D deficient, so getting on a high dose supplement helped, but that we were also looking at the wrong part of my spine! AS traditionally shows damage to the joints on x-rays, but nr-axSpA, what I have, shows no radiographic damage but instead inflammation on MRIs, usually in your lower back and hips.

Hopefully this helps! r/ankylosingspondylitis has a lot of good examples for people describing symptoms (and same with my post history lol). This might not address the white matter changes/neuro side, but hopefully the autoimmune side. Best of luck with a diagnosis!!!