Gosh, I'm sorry you're going through all this. This is what I found from the Mayo Clinic website:
www.mayoclinic.org/diseases-conditions/autonomic-neuropathy/basics/definition/con-20029053Be sure to read through all the pages there. It explains what this syndrome is, symptoms, probable causes, tests for diagnosis and treatments (therapies and medication).
From what I read, it can be caused by erratic blood sugar, many highs and lows throughout the years, so this is what your doctor meant, I guess. Are you on a pump? (Sorry, I can't remember if you said you are or not.) This might be an excellent reason to look into getting one if you don't have one already.
I wish I could help more. I'm sure the panicky feelings are terrible to live with. Has the doctor prescribed any anti-anxiety medication?
At least one good thing has come with this diagnosis (providing this is correct), and that is now your doctor knows how to treat this. This is why it's important for you to understand what's going on.
Maybe others have more information and can post for you.