You are suffering from insomnia. Insomnia can be primary or secondary. Secondary insomnia may be due to some psychiatric conditions like depression or some physical condition. If you feel stress like of study or any other that might be reason. You van be helped with medicines like zolpidem or clonazepam but that should be taken with doctor s advice and prescription only. for the time you can take a warm cup of milk before 15 minutes going to sleep. It helps in good sleep in my 30-40% patients. There are some rules for good sleep called sleep hygiene like.. regular schedule of sleep timing no day time nap avoid smoking avoid alcohol avoid tea - coffee before sleep Don t do your work on bed, use bed for sleep and rest only light music while u sleep can help You can search on internet more about them and can follow it.