Alprazolam is the medicine for it.
But it is highly addictive and should not be used without a doctor's advice.
Try to cure it without the use of medicines, of course you can do it.
Make yourself tired the whole day..keep busy all the day for a better night. Maybe you won't get good results the first few days, but be sure, you will succeed in a very short time to overcome insomnia.
Good luck.