I need help with a breast reduction question

So for years ive been wanting a breast reduction the idea is to get insurance to cover it but i cant tell if im big or average cup size. I have the symptoms like back + neck pain even went to physical therapy for lower back pain, I have horrible posture. No matter how hard i try i cant keep my shoulders straight for more than a minute (my physical therapist almost shot me because of how offensive my posture is, didnt even introduce herself before calling me tf out) i get rashes in the summer and i get the bra strap dip in my shoulders (but they go away after a few hours of taking it off). The internet wont tell me exact measurements for insurance and when i look up my size it always says im average even though i can never find my size in any stores. Anyway my size including sister sizes are 30f 32ddd/f 36d with my band measurement being 31

Im mostly asking because i dont want to go through a consultation just to have the insurance call me back and laugh at me. Cuz god knows i dont have up to 7k to drop on new tittys.

Edit: i would want to go down to a c or b cup ideally