I was 36J was told to lose weight and went down to 34J!!
I had a v supportive gp but had to emphasise every aspect to get my reduction. my first request was rejected so had to appeal. All those I know who have tried to get this op were also turned down first off. I think they do this to see how determined you are.
my grounds for the op were, physical - pain when exercising, working, just moving about, sores, dents in shoulders, I had to give up sport as it was too painful etc
and mental, I felt like a freak, my body was out of proportion, couldn't bf (my boob was larger than ds's head - I could hardly see him!)which led to pnd, had counselling and ADs which didn't help, I couldn't bear to have dh touch me as I felt such a freak, I also felt my boobs were a physical disability as they prevented me from living a normal healthy life.
I eventually had the op in January - yipee and am now a happy size 34dd
Tell your gp everything and be prepared to be knocked back. I would also 'sex up' your problems eg back pain is severe back pain etc iyswim? go for it and good luck