Seems that whatever our boob size is, we want something different. When I started 'developing' back in the early 1950's bras were sold via M&S and only in A B C cup sizes.
I was not overweight, but my boobs just kept growing. Indeed, I actually, very dramatically told my Mother that I was deformed!!!!
She managed to find a small lingerie shop who also stocked items from USA and actually measured customers. I was taken there (15 years old), and discovered I was a 36 DD. A properly fitting bra (very expensive), did wonders for my self-esteem, although I was still wearing jumpers two sizes too big to hide them!!! This shop even managed to find a strapless bra for me which gave me an excellent shape and support.
I used to hate swimming cossies - back then all in the same cup size (medium), and all my friends used to be able to take off the supporting strap, so as to get good suntan(!), finally, using this strapless bra underneath my cossie, so was I.
I can remember some years later, when one of my babes was born premature and I had a job getting her on my very ample breast, the midwife saying something about her having to deal with Everest. But I did manage eventually.
Some years after that I became very ill with Ulcerative Colitus and kept delaying having the operation which would give me a stoma and was being treated with large doses of Steroids. I lost a lot of weight - and my boobs became quite small for me - probably more normal. During this i was getting dressed to go to a special occasion in a dress I had in my wardrobe, purchased a few years earlier. When I put this on, it looked silly as it required my larger boobs, than I then had. I can remember bursting into tears and having to stuff cotton wool down my bra.
Thinking at the time....be careful of what you wish for.
As I have 'spread' a little in my latter year, my breasts look pretty normal now - 36 F, but do need so much more support . Even at night I now wear sports bras for this purpose.