I would like to add to the good advice that Susan has posted for you. I agree that you should visit your doctor for a work-up as your symptoms could be a result of many different conditions.
But to answer your question, a common test for the adrenal glands is called an Adrenal Stress Index (ASI). This test takes samples of saliva collected at 4 different times over one day and looks at the levels of cortisol. Cortisol is a hormone produced by the adrenal glands and is responsible for many different functions in the body. One of the common symptoms of low cortisol levels, which you are experiencing, is fatigue.