I do not want to alarm you, but your girl could have a serious condition called pyometra which is an infection in the uterus, particularly since you have not seen this in the 7 years of her life. It only occurs in unspayed females and can be very dangerous if not caught early. If she is not eating, I would recommend finding a vet to see her tonight. They may need to do an emergency spay surgery.
For more info on this condition, click here.
For financial assistance, go to www.carecredit.com which will allow you to finance vet visits over time with little or no finance charges. I hope your girl will be just fine, please let me know how she does, okay?
Warmest Wishes,
Reani
Cat Care Expert
20+ years experience with Cat Care and behavior problems, 3 years Pet Rescue