Possible reasons for this cricket pain in my neck?

Aleve and a hot, hot bath. Bed rest after, on your back

I had to give up sleeping with my arm up years ago because it screwed up my neck. Going with a thicker pillow let me sleep on my side without the support of my arm. At most, I’ll shove my hand up under the pillow, but I’ve got to keep that elbow low or I’ll pay for it.

I don’t understand what a cricket pain is.

Do you mean a “crick,” which is defined as
a painful stiff feeling in the neck or back?

As @thorninmud suggests, you have to experiment with a change in arm position with pillow arrangement assistance.

Better to avoid what brings on the pain than have to deal with medication and heat to diminish it. (I sleep on my side with a pillow between my knees, which is annoying when I need to turn over, to prevent lower back pain.)

Make sure your pillow is under your neck and head, and not under your shoulders. Definitely try some new sleeping positions. Try sleeping on your other side. It could be a disc in your neck that gets aggravated if you are in a certain position too long;flipping to the other side sometimes does the trick. The problem is if you are accustomed to sleeping on a certain side, in the middle of the night you might turn that way without realizing. I can’t sleep on my right without being in pain. As long as I don’t fall asleep on that side, I don’t have a problem. I seem to not naturally turn that way during sleep. Luckily, that is the case for me. Also, if my pillows are not high enough I can get horrible neck pain and stiffness.

Lastly, if you are noticing other muscular stiffness problems in your body in general it might all be related. Mine is significantly helped with vitamin D, but I recommend getting your D level tested to see where it is at if you are having muscle pains in general.