Exhaustion is caused by toxic liver and adrenals. The adrenal glands react from stress in your life. Too much stress over stimulates your adrenals and they stop functioning.
Toxic liver is caused by toxins that you might ingest, alcohol consumption, smoking, diet and the emotional pattern of anger.
Vitamin C and Panothanic Acid is good for the adrenals. And for the liver Lecithin 1200 mgs x 2 daily to start. Other herbs for the liver are Milk Thistle and Dandelion Root.