I stumbled across a condition called Autonomic Neuropathy today that sounds similar to what I've been experiencing. I've often wondered why my stomach problems always seemed to coincide with my faint feelings and lightheadedness. When I've asked cardiologists in the past about it they just said may heart issues shouldn't be affecting my digestion. It's funny that none of the neurologists I've seen have mentioned this as a possibility. While searching on this condition, it is often linked with diabetes. Even though I've never tested positive for diabetes, I have had problems with blood sugars. I've done some searching on natural treatments for it, and came across alpha-lipoic acid as a good treatment. I may try this but he one thing I found was that it can affect thyroid levels and since I'm on synthoid now because of my thyroid being low, I'm a little wary of trying it, but I'm excited about the new direction to try.
I should probably also mention that in May my doctor started me on Synthroid because they tested me for hypothyroidism. I felt even more tired after taking it and my muscles seemed really sore and shaky. Started taking my Adrenal C again because that seemed to help with my energy level a lot. Now I seem to be either wired or tired.