I am resetting my sleep schedule again, which I occasionally have to do. This time, I had a cough that kept me up late for a few nights. I always do the same thing: take melatonin and diphenhydramine--the old school antihistamine that makes you drowsy as heck--before bed. This is not dangerous or unhealthy, infact, getting some good sleep should probably be among your top health priorities. This technique always works for me.