I may be way off base here, and if so, then please accept my apologies and ignore what I'm about to say:
I don't think that how pretty you are is the underlying issue here. Having read the way you feel at these times, something else springs to mind. It strikes me that the deeper issue is that you feel invisible, or that no one is listening to you? Like... hmm... maybe you feel like you could be standing in a room screaming at the top of your lungs and no one even looks up?
This is just a feeling I get from the things you've said, but do you think perhaps that the reason you want people to tell you that you're pretty is because maybe you feel that if people think you're stunningly ravishing that they'll actually pay attention to what you have to say and really make the effort to listen to you?
You mention that where you are, that you feel like it's silent, or that you don't have a voice. Do you feel that people seeing you as pretty will give you that voice?
*hug* Honey, you're beautiful, but your voice has to come from within you, you know? Self-expression is more than just what's on the outside. What kinds of things do you like to do? What activities do you enjoy?