Cut out all energy drinks, caffeine, soda, sugary snacks, etc.
These things can mess you up and screw up your bodies natural patterns. Instead, drink water, milk, juices, or fruit smoothies. These are easier for the body to digest and use naturally. Once you body gets on a more natural/healthy diet, your body learns to cope without supplements and develops patterns. This makes it much easier to sleep, and get better rested sleep. My uncle who is a doctor suggests this to his patients experiencing similar problems. Only in certain cases has he had them conduct sleep studies because it didn't work.