Probably a papilloma.
http://pets.webmd.com/cats/tumors-cats
It needs to be checked out regardless, because even if it is benign it can rupture. That would be a terrible mess to clean up, and if it becomes infected your cat will die without treatment.
Sorry to hear about your financial troubles. I lost my job 2 days before Thanksgiving. Instead of just ignoring the problem, perhaps you should have sought some assistance several months ago?
If it is malignant, it probably has already spread to the lymph system or other areas of the body.