Severe Headache. Helps relieve the pain!

The pain pattern you describe is suggestive of a cervicogenic headache, where pain originates from the neck and radiates to one side of the head. Prolonged driving, poor posture, and physical exertion can commonly trigger this type of headache. However, as this is a new headache that is brought on by exertion, I would recommend a neurological evaluation to rule out other causes. If your examination is normal and there are no red flags, conservative treatment with posture correction, neck physiotherapy, stretching exercises, and appropriate pain medications is usually effective. Seek urgent medical attention if the headache is sudden and severe or is associated with weakness, speech difficulty, vision changes, vomiting, or loss of consciousness.