You are such an awesome person for doing this for animals. They need more advocates.
Every one of my pets was a rescue. However, two were from a breed-based rescue group because I wanted a specific breed. However, it was still a way to provide a home for a dog that had been abandoned.
I am very much a supporter of animal shelters. When I've had money, I have donated to them and it always made me feel good. I am not sure I could deal with the emotional toll of working there, so I admire you so much for having that strength.