Belly button rash...

I just got my belly button pierced a week and a bit ago and i was told to use bactine only...i got a small rash on about the 4th day so i tried to use salt water and bactine and put anti itch creams on it...it didnt hurt and its like a ring outside my belly button not near the piercing but surrounding my whole belly button..it turned into a flat red irritation and the doctor suggested cortisone cream but i went back to the piercer and he said i made it worse by using too many things and not to use the cream and just use the bactine..what should i do?! please please answer ASAP!