I am assuming it happens only on one side. It may be cervical spondylosis that's causing your symptoms.
You might need blood tests and additional imaging for further evaluation.
Next Steps
Maintain proper neck posture while sitting and sleeping. Isometric exercises for neck are advised.
Take 1 gm Dolo SOS for pain.
Health Tips
If symptoms persist/ get worse or / any additional symptoms develop, a neurosurgery consultation will be required.