The best indicator for fatigue is noticable fatigue and weakness. Have you noticed feeling weaker and more tired? Iron deficiency is also another very common cause of fatigue and twitching and also causes swallowing difficulties which you mention in your first post. Do you have pale lips and/or thick ankle/s, and/or lower back pain, shortness of breath, which might also be tell tale signs or iron deficiency? Restless leg syndrome from time to time?
The other idea I had was to source a good multi mineral so that you get everything you need in one tablet or formula.
Have you come across Dr Lam's fatigue site? Lots of good info here on adrenal fatigue:
The other issue too is the question of why you you developed the reflux. Many alternative therapists think that reflux comes from not enough acid production rather than too much. Why this occurs is deficiency leading to the stomach being unable to produce enough acids. Are you still on the nexium?
I know its alot of information, but the body is complex and often there are multiple deficiences going on. I would definitely ask your doctor to run iron/ferritin tests.