This is the one thing I have found that works when I can't sleep:
A teaspoon of olive oil taken orally.
It seems to lubricate my mouth and throat and help me breathe and swallow and relaxes my head, and before I know it, it's morning.
I keep a small squirt bottle on my nightstand- I find that I will not get out of bed when my head is clenched, even if I cannot sleep. But I can reach out one arm...