Dude. Seasonal affective disorder. I have it bad. Don't even want to get out of bed most mornings, and my energy level for the rest of the day is zilch. I am not generally like this, like, EMPHATICALLY. I'm working on it though, just really forcing myself to get out and about, and it's helping. Took a long walk on the river today, and have felt better ever since. You should look into it, it might explain your exhaustion/icky-feelingness.