Trouble sleeping at night?

Im having some trouble sleeping obviously or thats what I think anyway, I try to sleep at 10:30-11pm and wake at like 7 but I always feel exhausted when I get up I have resorted to taking NO DOZ to get through school and homework but the cycle repeats and when I go to sleep earlier I still feel tired. I HAVE TRIED MEDTATION AND RELAXATION TECHNIQUES NONE OF IT SEEMS TO WORK.