how do i give my rat food and water? Her neck is broken and she just breathes and lays down

Hi Soph. So sorry to hear about your pet. Your best course of action at this point is to get her to a vet so that can put a brace on her neck and ensure she is getting food and water. I realize that might not be an option for a rat but it's really your only choice. How do you know she has broken her neck? This really sounds very serious so I would encourage you to get her to your vet as soon as possible.