Perhaps consider using your skills to create good story telling for your shelter to attract volunteers and part timers. Running ads can help to create in-flow of donation as well, be it in monetary or food supply to help you keep the place running. After seeing an advertisement for a dog shelter on IG several times, my friends and I pooled together a lumpsum, whereby 1 of us went to purchase bulk of dog food and personally deliver to the shelter. While it's only a "temporary relief" but the owner said at least with whatever provided, it could last them several weeks.