Fast track to Breast Clinic

Hi there,

I am 35F and noticed my right breast feeling heavier and different in august. I left it to see if it would go away and to see how I felt on and off my cycle. It all got a lot worse. 8 weeks ago I notice how much right breast is drooping low like it's been weighed down and the nipple is almost pointing down with it - it's not perky like the left. The constant ache pain in the same region started 2 weeks ago. Needless to say I went to my GP and now I am being fast tracked to the breast clinic. I don't have a lump as far as I know. But I do have thickening that is now really painful when prodded. The GP said I do also have some thickening on the left breast. But my right breast feels completely different. I can't explain it but something just doesn't feel right at all. I'm not someone to over react (hence why I waited) but I don't know if anyone has had an experience like this? My right areola has also gotten very large. I have never had kids but the position of my right breast looks very droopy and different. 
I have had a mirena for 15 years (4 different ones) not sure if that is a factor. 
 

Should I be concerned? I deal with a few chronic illnesses but nothing has ever felt this "not right" before as it does in my right breast. I'm legit worried.