I have a quarter ssize open sore on my chin

three days ago I had a small hard bump on my chin. the next day in the center was black and bigger in size .pain full. I put a warm used a warm cloth for about five minutes. it then became soft and open and clear drainage came out.when I woke up this morning the sore was bigger and had a white head .on the aides .now I am really worried the sore hasopened and my akin is’s draining and hurts . what is the