Rash under my boobs?

Hello! I'm pretty shy to write this but I don't know what to do anymore! I have pretty big boobs and for a while it's been red and burning under it. Today is the worse. I'm working and can't take off my bra it hurts so bad. I just went to the bathroom to look at it and it's almost the color of blood and it's wet and smells bad. :(. My doctor is on a sick leave so I can't see her! I won't post a pic because it's really gross. :( any ideas what I could do??

Thank you!