--like a stroke or other brain/vascular event than anything else, given the sudden onset and the presence of a definite midline demarcating symptoms; though given the head and face are excluded (so far), this might also involve pressure in the spinothalamic tracts or in the cervical spinal cord.

I don't understand why the VA hospital would be uninterested in seeing you--given the wide distribution and sudden onset this definitely seems a medical emergency.