I have been suffering from insomnia (along with plenty of other problems). It is also caused by adrenal fatigue so neuro calming herbs and supps don't work that well.
I was finally able to beat it with a single "recipe". It is even not a drug.
A traveler, friend of my father told me how he used to sleep in Norway during polar days. He put airplain eyes sleeping mask on his eyes and puts ear plugs in his ears. The ear plugs has doble function - not only limit the sound, but also warms the inside of the ears. And that plus the darkness make you sleep.
I know, it sounds crazy simple and you may not believe it works as I did. But after trying melatonin, valerian, breathing techniques, you name it - and nothing worked, that did!
Please, try it. At least it is simple and cheap.
You will be surprised.