tell my why I always feel tired

I'm tired alot. From the time I wake up around 6.30 to the time i come home at 2.30 and take my nap at 4.30. The only time I seem NOT to be tired is when my mind is being stimulated by physical sports, mind puzzles (like cross words) or when I'm doing something artistic (like writing, drawing, or playing an instrument.) Can someone tell my why I always feel tired because my only conclusion is that everything is too dull for me.