Whenever I have a tough time falling asleep, I read this verse out loud, to remind myself of God's care.
In peace I will lie down and sleep,
for You alone, LORD, make me dwell in safety.
I repeat it, over and over in my mind, and as that verse gets absorbed into my mind and heart, I can feel my tense muscles relaxing. I start to breathe deeply, peacefully. I remember that God cares about everything concerning us. He even cares that we have a peaceful night of rest.
Good night... Sleep tight... you are deeply loved.