Hi,
This seems a typical case of a stiff neck due to an improper sleeping position at night. The pain on one side and at the base of the skull, the pain beginning in the morning, the stiffness of muscles on one side, all suggest this.
You should not worry much for this. You can consult your Family Physician or Primary Care Physican. Such a consultation will be sufficient to take care of this. If necessary, they can refer you to a specialist.
Meanwhile you can take the following steps at home:
Warm compresses.
Rest to the neck - avoid leaning forward, do not use a high pillow, avoid any uncomfortable position of the neck.
Take Tab. Motrin 200 mg (OTC) if the pain is severe.
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