How are you?
From your symptoms it seems to be a migraine headache. Migraine headaches are throbbing headache which occur on one side of the head.
Do you have any other symptom like photophobia or ringing in the ears?
I would suggest you to lie down in a dark quiet room and apply cold compresses to the affected part. Avoid caffeine, bright lights and noisy places.
High BP can also cause severe headaches.
Please consult your physician as soon as possible. Take care!