Not to burst the sleeping bubble, but be careful with melatonin. In basic pharmacology they teach that a lot of it is placebo effect because most people are stressed, and they think they have a sleeping problem based off of their hormones, but in reality it is the stress. Melatonin actually is rendered ineffective if you are taking it daily, and actually can cause damage to natural melatonin hormone production because the body adapts to a new 'sleepy time influence.'
If you have a lot of stress, anxiety, etc, then consider seeing a doctor, because melatonin is very potent and can disrupt sleep even moreso. Actually, if taken in doses larger than 1mg, a portion of it will remain unsynthesized even into the morning, causing you to feel even more tired and groggy throughout the day.
So, go to your doc and get a saliva test to find out if your pineal gland is operating properly. If it isn't, then you actually have a legit sleeping problem. If it is working properly, then try yoga or have sex to relax before bed.