Every so often, I get incredibly exhausted and have to go to sleep at six or seven in the evening and usually don't wake up or don't feel refreshed until the next morning. I don't go to bed very late, usally around ten or so, and I don't don't very hard work. I am also seventeen. Also, every so often I have days where I feel just horrible and I don't know why. I'm not sure if anything's wrong or if this is normal, but please enlighten me if you can. Thanks.