Sleeping problems and neck issues

[SteveC116]

I'm aware this is very off-topic, but this is the off-topic forum. So eh.

For several months now, I have been waking up with a stiff neck that was curable by cracking it and a hot shower. Recently, however, the stiffness refuses to go away, and it is now causing me to lose sleep and get headaches. My sleeping position probably isn't that great. I sleep half on my side and half on my stomach and I normally have one arm underneath the pillow. Does anyone know any better sleeping positions that offer neck support, better pillows, or stiff neck rememdies?

Thanks.