I've been on this site for about 7 years, and I can't remember ever hearing about breast atrophy, so that's a new one. Perhaps that's the way your body reacts to the fake hormones, who knows. The rest of it is totally consistent with Mirena though. I've heard many that run into problems with their second mirena too. You'll find that the longer you leave it in, the worse your symptoms will become, and longer it can take to recover, so if it were me, I'd get it removed ASAP.