I have been told by my neuro at Hopkins that ganglia damaged from autoimmune disease (like Sjogren's) is typically permanent and not reversible.

Have you checked your BP when & while you stand (when you are actually having symptoms)? It's common for doctors to only check when sitting (even when the patient complains of problems when standing. You need to see what it's doing WHILE you're having symptoms. Have you had a tilt table?

You should have also checked your BP after taking the Midodrine (when having symptoms) to see if there is any changes.

I am not an expert on EDS, but I know it is sometimes seen WITH autoimmune disease and can accompany many other conditions. Whether or not it actually solely causes dysautonomia...I can't say. Never heard that.

Do you have any other unexplained symptoms?