Why do I never feel good?

I seriously never feel good. I have headaches almost everyday, at least every other day. Whenever I get 8+ hours sleep or even 6+, I feel awful. But if I get 2 or 4 I feel fine and dandy. I'm sixteen, almost seventeen if my age matters. I was depressed a lot and I get those feelings back a lot.. I'm a lot happier now than I was though. I have problems with weight and such, not losing it but with like eating disorder issues - to narrow it down. I used to self-injure. I can't fall asleep at night a lot. If I fall asleep early or even at 10ish I'll wake up at 2 or 3 or something and can't fall asleep again. But yet I'm constantly tired. But sometimes it's not a sleepy tired I guess.. Like I'm just mentally tired 24/7 because my mind goes crazy all the time, but when I get the normal amount of sleep for my age I'm exhausted and I feel horrible and such.