In my opinion Pretty you are looking in the wrong places. Stop being negative about being big, stop trying to work for agencies who will not promote you the way you are.
Big women can be just as gorgeous as skinny women, skinny women are not always that pretty either. If you are attracting the wrong clients it might be in how you advertise yourself. There are a lot of bigger escorts that do very well for themselves.
When I started in the industry i worked in a Working house and was surrounded by gorgeous petite girls two of them were part time glamor models. But the women who got the most work and who was more popular was myself and the lady in her 40's.
There is nothing wrong with women being "fat", "plump", "voluptuous" and utterly gorgeous. You do not have to be skinny to be attractive.
This photo of me was taken 1 week ago, do i look unattractive? And do bear in mind I am a size 18 bottom and 22 on top