You might think you are too short to model, but I just read a breakdown for an energy commercial that said, "SEEKING: AFRICAN AMERICAN LITTLE PERSON
African American male 20 to 40 years old. Expressive face with great sense of improvisation. He is a street musician who wants to work in the circus. One day while playing his instrument in the street a circus truck passes through and he starts to run after the truck. He doesn"t have enough energy to catch up to the truck and gets left behind."
You know if little people can book commercials and make $3000, I don't think you are too short to try to be a model.
The first step to being a model or being anything you want to be is trying. And just because it is hard and not easy doesn't mean you shouldn't try. It really just comes down to trying and self serving and being realistic with your goals and self.