I Am On A Antibiotic And Was In The Sun.

I am on a antibiotic and was in the sun. I now have a red circle about as big as a fifty cent piece on my forehead and it hurts to touch it...putting something cool on it helps, think it is a reaction to sun and meds. Is it possible just to have this little spot? what can I put on it to cool it down without hurting it further. I was putting on a antibiotic cream?