For me a softer foam pillow worked. Can't remember the name of it, but it is deeper at the top and the bottom. I tried a few and that worked with an older smaller one underneath. The latter I got in Germany many years ago.
I have had this, and I found it wasn't all bed related. I sorted out my workstation at work and computer seat at home - had to sit higher and have keyboard closer. In bed trained myself to sleep on my back and on my rhs. Not completely cured, but much better.