My breasts is sore and I have developed a high fever, what am I supposed to do?

Might be a plugged duct or mastitis! I got chills and a huge lump on my breast plus pus in my milk when I didn't pump/latch for 8 straight hours. Here's a good article on seeing if you have plugged ducts or mastitis: http://kellymom.com/bf/concerns/mother/mastitis/