Thanks for the detailed info.
Here are some possibilities;-
1-In fact the symptoms you are describing warrant the urgent need for evaluation,most probably it is due cervical radicuopathy,which means the nerves are being pinched at their outlets by the cervical vertebrae
2-Sometimes muscle spasm due to over work/minor unnoticed trauma can cause straighetning of vertebrae causing these symptoms
My sincere suggestions is the need for urgent neurological evaluation and following investigations at the minimum
1-Xray Cervical spine
2-MRI Cervical spine
3-May be NCS/EMG (Nerve conduction studies/electromyelography)
Further treatment will be modified based upon the result
In the meanwhile following can be helpful
1-Rest and physical therapy
2-Use of NSAIDs for pain
I hope the info helps
If you need further assistance feel free to ask
If you were satisfied,Kindly click ACCEPT,Thanks.