Nuerological insomnia and other issues

I am a 37M who has been fighting with progressive neurologic symptoms since late January 2026. It has thoroughly destroyed the quality of my life leaving me suicidal yet still consumed with trying to figure this out while I still can. Healthcare is moving to slowly and has been negligent at best. My Symptoms include severe insomnia, cognitive decline/brain fog, memory impairment, burning sensations in the extremities, and significant functional decline.
Notable findings:
MRI brain (5/27/26): "Prominent cortical atrophy and cerebellar vermis atrophy for age" with minimal diffuse meningeal thickening. No acute infarct or hemorrhage.
Earlier MRI (3/15/26) did not mention atrophy and was read as no acute intracranial abnormality.
CSF protein: 92 mg/dL
CSF albumin: 83.3 mg/dL
Albumin quotient: ~24.5
WBC: 1/uL
IgG index: 0.47
Oligoclonal bands: absent
RT-QuIC: negative
Total tau: 194 pg/mL (normal)
14-3-3 gamma: 3759 AU/mL (elevated)
Mayo autoimmune/paraneoplastic CSF panel reportedly negative
Sleep study:
N3 sleep: 0%
REM sleep: 3.3%
N2 sleep: 92.5%
Sleep latency: 96 minutes
One notable event preceding symptom onset was approximately 6 hours of exposure near an electric vehicle battery fire on January 31, 2026, though I do not know whether this is relevant. But this is when the insomnia began.
My question: What differential diagnoses would neurologists consider for the combination cortical/cerebellar vermis atrophy, blood-CSF barrier dysfunction (high protein and albumin quotient), severe sleep architecture disruption, and progressive cognitive symptoms in the setting of a largely non-inflammatory CSF profile? I am trying to pursue an FDG-PET pet scan and a academic toxicologist but this is highly difficult. There are other symptoms, such as severe weight loss from early February to late march and what I believe to be thyrotoxicosis that was misdiagnosed as hyperthyroidism. I also have developednhighly elevated HCT which I believe to from excess EPO that my kidneys have now started producing possibly in correlation to then car battery fire. Any insight here would be greatly appreciated. Thankyou