throb means pulse or beat strongly.the guy probably means he got a headache or something got wrong with his head

The beating of the heart makes blood vessels distend slightly. This creates a slight pressure in every part of the body that has a good blood supply. We don't usually notice this. When something hurts, the extra pressure causes extra pain. A "throbbing pain" follows the pulse and heartbeat. "Throbbing" often refers to sensations--painful or not--caused by heartbeat.

What is a throbbing headache? A throbbing headache is a sensation of pounding, pulsating, rhythmic, or explosive pressure in the head. It can affect all or just a portion of your head. The sensation of pain is subjective, meaning that each person experiences it differently. Some people may describe a throbbing headache as also being sharp, dull burning or squeezing in nature

It means you have a really bad headache. You can feel the blood going 'boom, boom, boom' inside your head - that's what 'throbbing' is.