I think I messed up! I have an injured wild baby rabbit...?

My dog brought this injured baby rabbit to my house. She is old enough to be on her own, but I have her because she definitely has a broken foot. She urinated, and there was blood in it, so she might have internal bleeding. We don't have enough money to take her to a vet. I put a large pillow case in a shoebox and put her in. I left water in there, but she didn't drink. I put the box on top of a lamp that's on to keep it warm. She can't hop. Any time she tries to hop, she just flops over. So...what should I do? Tape her little foot up and set her free? Keep her?