I should note that melatonin originally did not work for me, e.g. when I took it for a year in 2012. However, now that my other medication has been adjusted (e.g. lower antidepressant dose, addition of a mood stabilizer, no more benzos), it seems to be working very well. Other lifestyle changes that I've made: 3000mg omega-3 fatty acids daily, drinking chamomile tea (2-3 cups every day), cutting back on refined sugars and greasy food, eliminating alcohol, meditating a few times a week (20 mins per session), and yoga a few times a week.

Also, I keep dried lavender buds in my room (I use it as pot-pourri), and scent my bedding with lavender essential oil. This relaxes me. It also makes me more alert in general, which might seem contradictory, but it's not. Lavender is an anxiolytic, which results in better sleep and more alertness.

My suggestion: if melatonin isn't working, and you're desperate for sleep, consider trying it again after some lifestyle, diet, and med changes. It's working like a charm right now (my Naturemade supplement also contains natural relaxants, like chamomile, passionflower, lemon balm, and L-theanine).