Hello,
I apologize for the delay. This case is likely too complicated and difficult to provide much assistance via text.
In all of these cases I think it is best to contact as many local rescues and pet care providers as possible. This might mean reaching out to your local shelter and veterinary college. You can also start a go fund me page. Post on all social media accounts and personal accounts. Start with general practice vet who the rescues recommend. Give them a realistic budget for you. Ask about payment plans and payment plan companies like care credit or vetbilling.com. There are places to help. Keep trying and keep asking.
Hello,
The only way we can accurately diagnose any kind of mass is with submitting a piece of the tissue for biopsy or histopathology. If the mass is small and not bothering your dog you probably have a little time to monitor it and don’t have to rush to the vet. If it isn’t going away or if it is getting larger I would see a vet. In a dog this age I often talk about whether it might be a histiocytoma. These are usually benign and go away over a few weeks.