Insomnia does come from stress and anxiety, hon. They keep me awake many a night. Learning how to "shut off your mind" is not easy. Sometimes I feel I have to resort to medications, but I try to avoid them if at all possible. My first go to is Benadryl - a mild anti-histamine you can get over the counter at any store. I also have a prescription to a non-addictive sleep aid called Ambien. When I am greatly anxious, I have a prescription for generic Xanax.
I realize, with the exception of Benadryl, you don't have access to any medical care. So, you need to resort to some methods of relaxation and calming.
Some of these I have used to great effect:
http://www.wikihow.com/Fall-AsleepMy preferred method is ambient noise ... "white" noise or "brown" noise. I will run a fan in my bedroom window. Sometimes I will listen to a YouTube video of rainfall or ocean waves.
Here is one I recommended to a friend just yesterday. It builds during the first few minutes, the passes by and fades away at the end.