This situation should be caused by the strain of muscles and ligaments at the back of the neck. Generally, it can be gradually recovered. Will not compress blood vessels and nerves.
Suggestion:
It is recommended to have a full rest. Yunnan Baiyao aerosol for external use to relieve pain. After stabilization, do hot compress and physical therapy, and consider acupuncture to relieve pain, and relieve local muscle ligament tension as soon as possible. Take chlorzoxazone if necessary.