maybe he wasn't, ANS issues can be exactly what you've described - they need to do a tilt table test to see though =) or you can go to a dr who specializes in ANS issues to rule it out
http://www.medhelp.org/health_pages/Neurological-Disorders/Dysautonomia-Specialists/show/717?cid=196
it could be a combination of things...SSS with ans dysfunction and meds; sounds like its mixed
say you have SSS, which I don't know much about except for my own research, could it mimic something in the ANS umbrella or vice versa? POTS, NCS, OI, etc
I have quite a few possible things wrong - one is ANS dysfunction; NCS and OI with low bp but the past few months my normally low bp has raised into the 145/115 range and stayed there; for me that's fine so I don't faint. What has caused all of my problems, they still have no clue but we're working on it.
hopefully you'll get someone to find out soon what's going on and get you some relief, I know what a pain it can be.