If you have chronic fatigue, make sure you don't live in an area with heat and humidity combined. That's an unhealthy combination. If you do, try going to a cooler environment and see if that helps.
I know that in climates with heat and humidity combined, my body has problems losing heat, so I get fatigued and drowsy a lot.
wow. this would explain a lot for me, living in sw florida with temps reaching 105 and humidity at 100%. I am a LOT worse in the summer and seem to have more energy in the winter. Lately i have been sleeping 14hr nights on days off and taking 2-4 hr naps during the day.