I'll try to help, but first I'll need some answers to some basic questions that usually need covering before anyone can even start to guess at a diagnosis or cure.
1) How do you know it's not food? Does it feel like an object or objects that are too big? Or just very hard?
2) How long's she been like this?
3) Also how's her poop... Normal, runny, what color, does it smell normal or bad, any other differences from normal?
4) What's she doing that makes you think she's in pain and sick?
Stuff like that helps, a lot, to figure out what's wrong. Also stuff like what color is her face/crest, does she feel hotter than your other birds, is she eating or drinking, is she trying to lay down all the time or acting normal, etc.
Best wishes, hope she gets help in time.