For one, I'll be moving this to a our Off-Topic Discussion, since it's not really FeralHeart related.
As for a "stolen" social security number, that's always concerning. I would consider speaking to someone who would be able to help you, such as contacting the Social Security Administration (search for it online) to further investigate this. It could also have been some sort of prank, as well, but should be taken seriously either way.
As for your cat, why not take her to the vet? I hope she eats again, and both of you hang in there. It'll be okay. c: