Beating the blues without antidepressants

I am still looking for a reliable, harmless sleep aid. I don't have anxiety, depression or undue stress, my sleeping issues predate cancer by decades and almost certainly started with a child who slept through the night for the first time when she was 4 years old. Unfortunately Nature's Own gives me nightmares (literally, nothing wrong with the company to my knowledge). I have no problem in falling asleep, have been given all the stuff about REM sleep, sleeping through the night as a relatively recent thing in human evolution, etc etc, but seven hours straight more often would be rather nice.