This was probably a case of occipital neuralgia.
It is a type of headache characterized by piercing, throbbing, or electric-shock-like chronic pain in the upper neck, back of the head, and behind the ears, usually on one side of the head.
Usually, the pain of occipital neuralgia begins in the neck and then spreads upwards.
Following things can be reason for experiencing this kind of headache:
irritation or injury to the occipital nerves, which can be the result of trauma to the back of the head, pinching of the nerves by overly tight neck muscles, and, frequent lengthy periods of keeping the head in a downward and forward position.
As a wrestler you are in a risk group of people who can suffer from this type of headache.
This pain often improve with therapy involving heat, rest, anti-inflammatory mediations, and muscle relaxants.