I found a kitten, I am willing to foster but looking for programs to help with vet bills and adoption?

I found a kitten I believe is 5-6 months old outside by my garage and my stray cat i call Mr.Tom saw him and almost attacked the kitten so i grabbed it up and brought it inside. It was very malnourished but i have had it for a week now and she has gained weight (now weighs 5 lbs) and looks very healthy now. I am willing to foster and pay for food and litter, But she needs to be checked by a vet and given all her shots and be spayed. I can't afford it. I have to pay for 2 special needs dogs and another cat already. I was wondering if there were any programs that would be willing to help me with the vet bills and finding her a home. I am willing to fill out an application and do what i need to do to become a foster parent if need be, I wouldn't mind it. I have already called my local humane society and they say they were full. And I have tapped out all my family and friends for adoptions.any help is appreciated