The most likely ailment with these symtoms is pancreatitis. This can come on suddenly in a ten year old, especially if she ate any people food.
Other possibilites are severe stomacitis,impacted hair, liver or kidney issues. She may also have an abcessed tooth.
Whenever a senior cat hides, huddles, vomits or does not eat it is cause for concern because her immune system is not equpped to handle any issues or to go without food.
If you have an ER vet in your area, I would highly advise you to have her looked at ASAP.
Please let me know if you have any more questions. I will be more than happy to try and help.
Dedicated to Cats and the people who love them!
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