Having measured myself on the Be Cheeky website I'm coming up a 34D.
Yesterday I went to my local department store and tried on various size and brands of bras. Nothing fits!! I've tried 34 C, D, DD. 32 C D DD. The nearest fit I got was 32 D in a Triumph bra, but I'm still jiggling around like jelly, I feel like giving up 
I'm currently in a 32 DD marks and Spencers bra which is managing to be both too big, I can pull the band out easily two or three inches, and too small, leaves marks and the shoulder straps dig in. My breasts are also jiggling around like jelly.
Please help I need to find a proper full on supportive bra.