I had my university exams 1month ago, due to which I had to stay up all night for around 20 days. During that time i stayed up all night, Took the exam at 10am to 1pm and then slept at around 2 pm. And then wake up at 8:30-9:00 pm then again the same. Now my exams are over and i am unable to sleep at normal time, despite all measures. Currently my body urges to sleep around 7 am but i go to classes and sleep around 2 pm and wake up at 8:30. Can i take melatonin for my problem if yes what dose will be appropriate.