Well,it seems you are already doing all you can without taking it to the vet. Please take it to a local humane organization or vet who will be able to help it. It is likely in pain and could be suffering and if you have the cat, please take it somewhere to be cared for. I am certain you can find a place to care for it without leaving you financially responsible. If you do that, however, do not expect it back. I hope you find it in your heart to seek help for the cat.