If you haven't watched this, it's well worth the 50 minutes of time to see. Mentions dysautonomia and obviously lots of neuro issues. I found this on a Mayo Clinic blog, so they clearly stand beside it.
I saw Dr. Cheney for 15 years, and during that time he prescribed B12 shots.
Now I use sublingual lozenges, (instead of shots) from Whole Foods, (beware of where you buy vitamins and supplements, as many are sourced from China and southeast Asia). They may say they're 'distributed from Ohio', or any other U.S. state. but they can be sourcing from China...So if you're buying from Costco or chain drugstores, and not a reputable health food store, beware.
Best,
Questus