Get used to sleeping on your back
Sleeping positions are up to you, and some people are used to sleeping on their sides and can’t sleep if they are on their back. Well, if you can sleep on your back, it will be a good position to maintain spinal alignment and stay comfortable all night long. If you have recurrent neck problems, you can even use a neck support pillow and place a pillow under the arms to reduce neck strain.
If you don’t want to stop sleeping on your side, try to use a pillow that is not very high. Otherwise, you would be adopting an awkward neck position to one of the sides. A medium thickness of 4-6 inches works fantastically in such cases.