"Tossing and turning."
One of our daughters currently has problems sleeping --- she finds it hard to fall asleep, and she wakes up easily and then panics. We do what we can to re-assure her and give her stability, hopefully it's temporary.
When she talks about it, she keeps using the phrase
"I'm tossing and turning and can't sleep."
I find that so sweet. My wife and I never use this idiom, ever, and when she is awake she just lies there and neither tosses nor turns. But the phrase is in the air and saying it somehow seems to anchor her. I love her so much.