Go out in the Sun often.
How much exercise do you do?
Do physical hardwork in the day.
Create a strictly Scheduled Routine (eating, studying, working, household)
If you weren't able to fall asleep at night just wake up normally at sunrise, open the windows, go out for a walk, have breakfast and spend the day as if you have slept. Don't take any afternoon nap only touch the bed at night.
Most importantly, before putting yourself to sleep, write down a list of things which get you anxious while sleeping on a paper and throw the paper in dustbin. Tell yourself those thoughts won't come tonight.