About 4 days ago I found a bump. It looked white in the middle so I tried to pop it. Well nothing so I left it alone. Well yesterday I tried popping it again and nothing. It popped but only clear stuff came out. I then cleaned it and skin came off. Now I have a red circle that burn when I touch it. Its like a sunburn. P.s. I have only had one sex partner sence July of last year. What could this be?