Hi, I Have Been Having These Weird Pimples On My

Hi, I have been having these weird pimples on my breasts. I found one tonight and it was leaking blood and puss. Its very tender to touch and it has this bruise around it. When i push on it, it feels a but hollow like there is a ring around it underneather the skin if that makes sense. Idk they are and how to take care of them.