Sleeping disorder

Im writing this 3 hours before i have to go to school, because now i've been up the whole night without being able to sleep. Its been like this for a long time, but its even worse after the vacation. For some reason i seem to have tons of energy at about 10pm-6am, then i am a zombie the whole day even with good sleeping routines. A few days ago i went to bed at 1am and woke up at 8pm, and i was still very tired when i woke up. I have no idea whats causing this, so i wonder if any of you have any tips on how to get sleepy? Do's and dont's? I've been seing a doctor many times the past year because of this, but they all just say the same: go to bed at 11, eat healthy food and exercise. Belive me i do all of this but nothing seems to work. I asked the doctor for sleeping pills, but no matter what i do she refuse to let me take it. Its not really a big deal, you can buy those kinds of pills in stores in countries like USA. She just lets me take anti-depressive pills wich are supposed to help, but it makes things even worse because i can sleep at the night, but im a robot all day so i quit taking them after 2 nights. I need to find another way to get tired i guess 
