(facepalm) You really can't be left alone for even a few seconds unsupervised can you?
Eating rust (iron oxide) could definitely make you sick. This is something a doctor would be better able to answer than random people on a chess site. In a small amount accidentally eaten, it is probably okay, but again, I'm not a doctor. This definitely sounds like potential food poisoning or at least bacteria to me.
Omg Accidentally I ate some