What Causes Severe Headache After Masturbation?

Sir, i am 38yrs male happily married having 2 children with no sexual problem of any kind. Yesterday while massturbating quickly I had severe headache for almost 30-45 sec while I was ejacuating, that was for 1st time and was unberable, I had a history of low BP problem. My BP remains in the range of 60-125.