I was at a Qigong class where we were doing a form called the Post. We were instructed to go as low as possible in the stance. In a flash the whole top of my head (like a cap) was in pain--like shooting little knives. I saw a "star" and became light-headed. The shooting pain was extreme and intense. I stood upright and began deep breathing, but it took 15 minutes for the excuriating pain to disappear. I have never experienced anything like it before. It was scary because it was so intense and painful. I felt like I could have passed out if I hadn't the presence of mind to breathe deeply. I'm concerned there might be some kind of clot or tumor. I have a 50 percent blockage or so in my left vein in my neck.
I hope you found an answer about your headaches. I know that headaches have a wide variety of causes, and that physical exertion can also trigger some types. However, I am just a layperson. Did the headaches repeat or continue? Did you ever consult a physician about your experience? If you did, would you consider returning to the community and letting us know what you learned? I am sure your experience would be valuable to others.
In any case, here are some links that might help you learn more:
Migraine and More - Looking Around HealthCentral - July 29, 2014
Migraines, Exercise, and Intimacy
By no means am i a doctor, i am on here looking for answers to scary things too. I am not saying this is or even could be related to this in your case, however, my cousin has just had a few episodes like this. Have you had an MRI of your head done? She found by MRI that she had...and i dont know exactly, but something kind of like a small hymangioma (im not sure of this spelling) like a small clot in a part of her brain. The symptoms were as you have explained them, and progressively have gotten worse. They told her depending on exactly were this is in the brain, is whether or not you can easily medicate and deal with the issue. She was told it is not as uncommon as people think and that some people have them since birth and never know it. But i would ask if maybe an MRI would be something they would do. Doesnt hurt to rule out and ease minds. Hope everything works out well for you, and please update if you can.
This could possibly be from a pinched nerve or Migraine Headachs as my wife get's these,or possibly alot of stress too. Jim