What kind of doctors have tested you for adrenal fatigue?  Traditional doctors do a stimulation test that will be abnormal only when the adrenal gland is severly non-functioning.  Anything else they would consider normal.  Non-traditional practitioners will use a saliva test to measure your levels of cortisol during the day (usually 4 times).  Those levels can then be used to see how well your adrenal gland is functioning (or whether it is in the early stages of fatigue which shows hyper-functioning).  Mild adrenal fatigue can be treated with certain supplements.  More severe cases can be treated with prescription hydrocortisone.  Overall stress on your system leads to adrenal fatigue.  The stress can be from lifestyle or from food and environmental allergies/sensitivities.  Proper treatment can make a world of difference, and I would encourage you to find someone who can test you properly.