I have found one asmr video that I find really relaxing and I made a YouTube video of it playing a bunch of times. The light from a screen is also nice so you aren’t so surrounded by the dark.
Well, you must have a sleep schedule, stay active, avoid caffeine and alcohol, avoid beverages and large meals… If this doesn't work out, ask for assistance in any medical facility.. But first try that out
Prayer and meditation helps me. Psalms 34, 3,4, & 91 are my favorites. Guided meditation for safe place helps as well. Or listening to nature sounds.
I find that for me, the best way to fall asleep when I'm anxious or scared is to first calm my fears by praying. Ifbafter a prayer I still can't sleep, I listen to soft music or nature sounds. That puts me in the right mindset. If you aren't religious and praying won't soothe you, then meditation or journaling might help as well because they get your thoughts out of your mind. The same principle might apply to talking to a friend.