Hi Lottie,
Do get to your GP to get it looked at again as it sounds like the infection has recurred.
Honestly, the chances of it being IBC is negligible, especially as you are so young.
Google is best avoided on this as it only causes a load of unnecessary anxiety & any search of breast symptoms will only lead to cancer which is the least likely outcome.
Anyway, do get along to your GP to get it sorted out & do take care.
ann xx