OMG I have never heard of a reaction that bad! How awful for you… to have such a horrifying reaction… down there.
I was about the same age when I went horseback riding all day. My abs were so sore the next day that I could barely move. That night I applied Heat linament to the muscles… stripped down and went to bed. I woke up a few hours later in the fetal position and my… erm… crotch was on fire. Excruciating pain. I realized the ointment had rubbed off onto my family jewels. I ran to the shower and tried to wash it off but it only seemed to make it worse. Eventually the burning pain subsided and I learned a valuable lesson that night.