A slightly difficult question...?

I know I've always been the woman who answers all of the interesting sexual and from what I know, biological questions to you when I log on. But I've had a problem today that I can't explain. I should state my my stats first.

5'2", 148lbs. No major illnesses other than just been over a cold and a case of pinkeye. Mid-twenties.

Today while beginning to have sex, I felt a splitting and excruciating pain from my neck through the back of my head that made me ask to stop. And trust me, I've even played through leg cramps before. Then I started to sweat and he shoved me into a cold shower and brought me water and a couple ibuprofen.

I think I had a neck spasm that attacked me and sent my body into overdrive. It was about ten hours ago and my neck and shoulders are still killing me though my head has gone down to a dull roar but my whole upper back feels twitchy. I've taken half of a pill of prescription naproxen that I had left over and it doesn't seem to do anything for the pain or muscles feeling as though they may cramp again.

Preferably an educated or knowledgeable opinion on this, "go see a doc" makes you look like you're just working for an answer count.