You normally can turn your head 90 degrees right or left. If this is all of a sudden limited, probably with pain, you most likely strained your neck.
Neck Pillow Studies…
If you believe what someone is saying and also confirm it for yourself by trying it; that is the best way to figure that question out. Here are a couple real studies that give us some proof too.
What Happens When You don’t Sleep with the Right Pillow?
Not having the right pillow to sleep with can lead to headaches, neck pain, stiff neck and everything that comes with a lack of sleep.
Consider Changing What You Sleep on If You Cannot Sleep: Check Your Pillow
If you cannot sleep at night, think about changing the pillow you sleep on.