Couple of questions:

1. Are you certain your neck is suffering as a result of your default sleep position or are you assuming?

2. Do you sleep well on your stomach?

I guess what I am saying is make certain you need to change before you upset the apple cart.

I was a stomach sleeper and had to change...the back side of my head was what was left unbroken, so it can be done, I had to get a softer pillow that would fit in the hollow of my neck and go around the sides of my head to sort of support it.

Bud