I also take Melatonin 3mg, but not every night. Magnesium is good for feeling more relaxed. If nutrition is lacking I'd toss in a good daily complex of B vitamins. Food allergies can cause sleeplessness. A simple fix like cutting down on late night caffeine and sugar can help.
First things First, wake up in the morning, drink water or a small glass of OJ. Eat some toast, bacon and eggs. Take a B complex 100. At lunch eat a big salad with some chicken. Go out and do a 30min walk. Eat a good dinner, perhaps a salmon to get those Omega-3's, or take Krill/Fish oil ect..
Two hours before bed get away from the TV and the Computer and take some Magnesium and Melatonin. If you find yourself awake after a few hours in bed, don't stress about it's probably just a temporary sleeping cycle. Just get up, read a book, chill out and try to sleep again later.
There are some things you might want to check on that could be causing your sleeplessness other than just simple stress. I know when I moved to do some schooling the water in that area was bad. I didn't notice much at first but over a few weeks, months, ect.. my sleeplessness got worse, I suspected Fluoride. So maybe too much fluoride is disrupting the pineal gland? lol. Easy problem to avoid without going insane about it. I bought a fluoride and chlorine shower filter off of Amazon and a Pure Filtered Water Pitcher from clearlyfiltered.
There are neutralizing antidotes to common allergens. Yeast allergens need B1, B6, zinc and Lysine. Wheat allergens need Omega-6, Omega 3, B1 (Thiamin), B6, Magnesium, and Histidine. Most Milk and Meat fats need Biotin, B vitamins, Sulfur, Methionine, Cysteine, Taurine, L-Glutamine, Threonine and Carnitine. Ect.. I'm not sure I'd buy all of that stuff because of the cost. Just keep it simple and eat organic foods when possible. But sometimes a fasting with just water is a good thing.
Wheatgrass for me helps promote a long nights sleep. I've heard that wheatgrass turns the fluorine in water into harmless calcium-phosphate-fluoride compound, but I'm not 100% sure about that being a fact.
During these stressful times at school when your brain is using up all those nutrients, you need to eat better and avoid that sugar and I know it's hard to do while on the go. Your mind is swimming with big ideas, the endless reading and paper work feels like it never ends. Your eyes hurt, your brain hurts, your neck hurts.. ect. Just stop over thinking.. Let it all go.. Get some fresh air and sunlight. Turn that brain off, dial life down to relax..
If you find yourself still struggling perhaps a trip to a doctor might be a good idea. You never know, there could be something going on with your health. I wouldn't worry about it though, these things are normally temporary while under stress. We have a few more weeks of warm weather, perhaps take a trip to the beach for a day, have some fun, put those toes in the sand, whatever it takes to distract your mind from the daily grind.