This is something I have always struggled with. Spent most of my time originally in men's sports clothing. Triathlon is even worse. It seems that anyone over a 16 can certainly not do sport. Many years ago it was a size 14 cut off. That was an XXL!
I manage to find bottoms now but still struggle with tops. My main problem is wetsuits. I have skinny arms and legs but big boobs. They cut off my breathing but hang off my legs and arms! Much fun