Severe sexual headache. Any information!

Let me first tell u, my problem is kind of odd. for the last one week, I'm having severe headaches at the back of my head during orgasm. it first happened right after orgasm and was so severe it felt like someone is kicking my head with a bat. it just happened out of nowhere. it stayed for almost 15 hours. it was the worst headache of my life. never had such experience. after two days again it happened. though this time the severity was much lesser and stayed for lesser time. now I am so scared that I stopped having sex. I did some information gathering on the internet and found out that these headaches are often harmless though sometimes can be symptoms of serious issues. any information regarding this would be very much appreciated. thank you. ps: i had a small accident 3-4 months back resulting a skull fracture and got two stitches.