I am a C and I have exactly the same problem. I often thought the same, that there a two conflicting ideas to resolve! Beeing shortwaisted and having a wide hip. My best solution ist, to wear top and bottom in the same color, this way there is no horizontal line anywhere. Often I wear a vest above it, either above the widest part of the hip or a little bit below. If it is below, I try to wear tighter bottoms like a pencil skirt or leggins or fitting trousers. Sometimes I think, I am very limited, not to be able to tuck in shirts or to wear shorter tops. But other days I just think I have the opportunity to be more creative with my limited choices. A good idea also is to have a nice bag hanging on my shoulder, not lower than my hipbone.
Have a nice day and enjoy to be creative!