TMI (pic) PLEASE NO JUDGEMENT, I’m super uncomfortable with showing this.

Alright, so I was 15 or 16 when this thing showed up and it started out like the one under my nipple, then it like burst open and has been like this since (I’m 22 now) I went to the dr about it and she didn’t do anything. Idk if it means anything but my right breast (one in picture) is nearly twice the size of my left one and after the thing burst open I noticed another one right under my nipple? Anyone else have this or anything close to it? Any idea what it is?