It's always a bitch when you fuck up your anatomy via the crime of sleeping funny. One time a hotel pillow got me so I couldn't turn my neck much to the left for a few days.

I respect that I'm probably not helpful, but would tiger balm on the relevant vertebrea loosen the area up for movement? Or is too loose the problem? Swear to god it's how I fixed my neck, but it's a whole other ballpark ik.