Why have you decided to do this without a Humane Society backing you? Have you talked to them? Can they be of help?

If not, maybe another shelter or cat group can help.

Your vet may take payments - or, as I just suggested to someone else, Google "Care Credit". It's a loan for pets (and hoomins) health that charges no interest on whatever is paid back in 3 months time.

Good luck - please keep us posted!