I'm sorry for your trouble. We all know it is frustrating. A fast onset is cause for concern and you need to move quickly, IMHO. Think you may have been exposed to any toxins? Is there any history of neurological problems in your family? You may want to visit a specialized facility like Mayo or Cleveland Clinic, or there are others, where they can do more extensive and specialized tests. You may start taking vitamin B-12 as methylcobalamin, 1000-5000 mcg per day.
Ron