Hi, So For The Past 4 Or5 Days I Have

Hi, so for the past 4 or5 days I have had what my mom thinks is either a boil or a spider bite on my butt close to my thigh. Everyday we've been doing hot compresses buts its not really working. Today the skin around it started pealing off and there's now a new second hole on it which is black and very deep. Its red around the whole thing and that goes out for about an inch around. When squeezed a small amount of pus comes out (sometimes really hard to get out) and blood and a clear redish or milky liquid. What is it and what do i need to do? Please and thank you for the help.