Fix sleeping problem?

Lately I haven't been able to get good night sleep, i mean im like 16 n 1/2 n when i try sleeping at around 11:30pm i seem to juz stay awake for two hrs, then i kinda sleep but then feel kinda awake at the same time-its like im juz half asleep, then i wake up at 4am n stay awake for an hr or 2 again then am like totally out till 9am, is there any way to fix this? as far as i know im not stressed or depressed or anythin like that, but its rlly ruining my basketball practice this summer, is there any way to fix this? i don't want to take any medications though becoz my friends say i'll become dependent on it