I was diagnosed with post viral syndrome almost two years ago. It took months to get appointments and tests run. After all the blood and nerve tests. I have a lot of tingling and numbness but not as bad as you describe. I have headaches nearly every day. I got my symptoms following having the flu in April of 2019. I see both a neurologist and an immunologist. The immunologist discovered that I have an immune deficiency which is probably why I developed post viral syndrome. He has suggested that immunoglobulin treatments might help but it is difficult to get the insurance companies to cover.