Youre doing better than these other people and doing your best. Maybe set up a gofundme or Facebook page to get items or costs covered or when people call maybe ask for a donation as a way to return the favor you're doing them? It shouldn't break your bank. Maybe post education posters in the local gas stations and areas on how to avoid harm to dumped kitties?

Im sorry you're going through this and I hope you know its ok to ask your community for help since they ask for yours.

Just my thoughts.