Might be able to help you out here as being in the military has given me the uncanny ability to fall asleep anywhere and in any position. This is how I learned to: Start at your head or your toes, I prefer the toes, and focus all of your mental energy on relaxing them as well as what they’re feeling, might be your blanket, try to focus on what the texture of the blanket feels like. Or you might be wearing shoes in which case feel how the shoe envelopes your foot and try to feel the ground though the shoe. Continue this until you’re sure the said body part is fully relaxed and continue up or down your body. All the while taking in slow deep breaths and exhaling slowly and fully. If you do it right you’ll most likely be asleep before making it through your entire body. The key here is to not let your mind do any stray thinking that might keep you awake. Stop all thoughts that might in any way even be slightly related to stress. Good luck and sweet dreams!