Shelters or free vets for sick stray cat?

I live in an area where people frequently dump their cat, and there it is another poor soul. She’s sick the first day she came into our house (3-4 days ago) she ate a lot she was starving she was even in the trash everywhere, then she stopped it all she stopped eating stopped drinking now she’s so weak and keeps throwing up everything even water :( I really have no money I’m a student I’d appreciate if someone could give advice/ recc vers and shelters that would help.