Causes Of Fatigue
Here is another cause of fatigue, which I wasn't aware off: dehydration. You may think that is out of the question, because you drink a lot of fluids, but when those liquids contain caffeine, you better think twice; too much caffeine acts as a diuretic. Therefore, make sure to drink enough other, non-caffeinated fluids and eat foods which are high in fiber, because they absorb and retain water.
Fatigue is another consequence of depression. A depression can occur as a result of too much sorrow, stress, hopelessness, etc, but it can also be seasonal; many people experience depression during winter. Exercise can help lighten the mood, if the depression is not too severe, and in case of the latter, a light box or spending at least 20 minutes outside in daylight can be very beneficial.
Another excellent cure for beating a depression which is not caused by lack of sunshine is pointing our minds in a positive direction. Instead of lingering on the bad, let's try to focus on the good. God gave us more then plenty to rejoice in!
Finally, brethren, whatever things are true, whatever things are noble, whatever things are just, whatever things are pure, whatever things are lovely, whatever things are of good report, if there is any virtue and if there is anything praiseworthy—meditate on these things."