Late in the thread here, see lots of stuff but no sure fire methods to kill insomnia, and as for some of them there is a back story that is up to OP's due diligence to determine suitable in his situation.
Maybe some basic stuff to stop insomnia should be mentioned up front, before considering Ambien, which is dangerous shit.
First and foremost, it sounds like OP might benefit from being on a normal, regular sleep/wake schedule. You don't have to be Charles Darwin to figure out what schedule is best for health and well being. Staying up all night is a personal choice, but also very unwise to make it a habit and expect to cure insomnia.
From experience on a midnight shift for a year and another job working a rotating shift schedule, that is a inevitable slow motion suicide for health. You will have accidents. You will get sick and sicker. You will be out of sync and like a mistreated machine you will break down Last but not least, on a night schedule, good sleep is almost impossible.
Unless you are working a night job, you should be in bed at about the same time every evening, the earlier the better, and give yourself seven hours minimum.
In order to fall asleep and stay asleep, It is "very" important to be in a quiet place and to have the room as Dark as Possible. Use earplugs and an eye mask if you can't control the amount of noise and light.
Next is the comfort of the pillow, the bedding, and the room temperature. There is a delicate balance of these elements to achieve an ideal sleep environment.
Do you have a bed partner? You might be better off alone.
Ok, this is TL;DR but to sum up, OP should not look for an effortless guaranteed sleeping solution that will consistently beat insomnia, not without covering these basics.
Finally for anyone wanting to fall and stay asleep---> Strongly recommend exercise to exhaustion, in fresh air and sunlight. Also niacin B3, the kind I take says on the label "for heart health", that is what you want. One last item would be magnesium, such as the newer biglyconate type available online.