Your size has nothing to do with your chance, it has more to do with your own will. And how much time and effort you put into it :) I suggest getting a compcard, getting headshot, keep working on it.
Another big part of finding opportunity is to not expect someone else to do the work for you. Not even an agency. Many print models make their own compcards, themselves. They go to printing services and print compcards. Actually this is how a girl gets an agency, by mailing their compcard. So I suggest making a compcard, mailing it out, and hustle, hustle, hustle. Don't think that mailing one time is enough, it might take three different mailings with three different cards, but if you want something you must not give up. There is marketing involved in modeling.
Shorter models can find opportunity modeling but it is work.