Hii , Welcome To HCM & Thanks For Asking Your Query Here
from the medical History You Provided it seems that most probably you have sprain in ur neck which might be caused by improper sleep positions or stretching or a muscle in ur neck
you should provide proper rest to ur neck muscles & if possible please wear neck support band (
cervical collar), along with this apply heat packs and taking muscle relaxants like thiocholchicoside will help u ease it
in older ages this type of pain may also indicates
Cervical Spondylosis which is caused by wear and tear of the
cartilage and bones found in your
cervical spine in your neck
If your pain and discomfort does not respond to what have been mentioned above and it gets even worse and start to interfere with your daily activities
i would strongly suggest you to see a neuro
spine surgeon , he will examine you thoroughly and May opt for an X ray , CT scan , MRI , EMG , NCS to rule out underlying medical conditions
I hope it help
Thanks & Get well Soon