i had long hair and had it chopped off last year. i too have what i like to call a "fat face" but others call round. i went really, really short(she used clippers in the back). i love it! i have had alot of people tell me it brings out my high cheekbones. i say try it, you may be pleasantly surprised.
keep us up to date and pics please.
i also think short hair would look awesome on you (YOU have the face for it)