Really need help!!

I had been having some Lower back pains for a couple of days, but thinking it wouldn't affect me, I masturbated. Immediately after reaching climax I got a sharp pain in my lower back and head. Last night, I was hit with a horrible headache and nausea along with the pain in my lower back. I went to sleep and the nausea is gone but the other two symptoms remain. What is happening ? Help?