Another possibility is sleep disturbances (like sleep apnea, imbalance of rapid
eye and non rapid
eye movement sleep etc.). You may sleep your customary 7-8 hours
and yet feel fatigued. You need sleep studies to rule this out. Other possibilities are chronic fatigue syndrome, depression, low Vit b12, low iron, low calcium, sodium and potassium. Hyperthyroidism too causes increased sweating and tiredness. A comprehensive investigation is required keeping all the points in mind.