STAFF INFECTION

IM A 52 YEAR OLD WOMAN WHO IS A DIABETIC AND A HEART PT  I HAVE A LUMP IN MY GROIN AREA IT STARTED OUT THE SIZE OF A PENNY AND GREW TO THE SIZE OF A TENNIS BALL  I WENT TO THE DR AND WAS PUT IN THE HOSP GIVEN IVS AND FINALLY A SURGEON LANCED IT  OPEN  THE DR SAID IT WAS A STAFF INFECTION  WITH IN 2 WEEKS IVE NOTICED ANOTHER LUMP THAT IS ABOUT THE SIZE OF A PENNY AGAIN IVE BEEN ON IV ANTIBIOTICS AND PILL FOR GOING ON 3 WEEKS NOW  I WOULD LIKE TO KNOW WHAT CAUSES  THESE LUMPS AND IS THERE ANY THING I CAN DO TO HELP PREVENT THEM FROM COMMING BACK AND WHAT ARE THEY CALLED MY DR JUST SAID A STAFF INFECTION.    THANK YOU VERY MUCH FOR YOUR TIME.