I'm glad you found out what it was.
Almost 2 years ago I ended up going to the ER because I got like that and it wouldn't go away.
It was at night, I was up flipping through Instagram on my phone, in the dark. I'm pretty sure that's what triggered it.
If I kept my head pointed straight ahead, it was ok, but after I went to bed I couldn't turn my head either way without feeling nauseous + dizzy.
My wife drove me to the ER, of course it seemed like forever until they actually fixed it.
They did the procedure srt mentioned, which I don't remember the name of.
They leaned me back and reset something in my inner ear.
They had me get some dramamine.
I never could read in the car as a kid. Still can't! I have to look out the window to stay oriented.
I get a little dizzy/nauseous on the creeper if I lean my head back a certain way, too.
Thank God I didn't get that way and stay like that, I don't think I could take too much of that.
I'd have to have somebody drive me to the river so I could jump off the bridge.