Dog distress - Seeking ideas

Sorcha is still whining incessantly. I see from my journal that this has been going on for more than a month -- probably more like six weeks. I'm taking her back to the vet on Wednesday to get her thyroid levels checked.

Other things we've tried:
I moved my bed so she can see me better from my crate.
I turned a night light on overnight.
Sitting with her on the couch to watch TV and movies. Three feet away in my chair isn't close enough-- I have to be like, touching and petting her to stop her whining. And I can't type with her on the couch because she paws at the screen and keyboard.
Distracting with treats.
A thundershirt. (Had to take a break from the shirt today because I may have left it on too long yesterday.)

The worst is when I try to lie down for a nap and she won't let me sleep.

I posted on the Greyhound bulletin board-- run by the rescue group-- asking for advice. So far, no help.

She does not seem to be in pain, not that I can tell. She still runs hard at the park, some days, and still hops in and out of the car, walks fine, etc. It seems more like anxiety, but that strange thing it how it started relatively recently.

Any ideas??