HELP!! ASAP. ANIMALLLSSS!!!?

Okay so, I was taking my boyfriend to work and I saw what appeared to be a box in the road, so I drove over it not wanting to hit it, when I looked in my rear view I saw that it started flapping...so after dropping him off, I drove slowly by and realized it was a duck. I couldn't just leave him there...so I took him home. I have him wrapped up in a towel, and he was bleeding from his nose, and his left eye is all funny. I think he can still see out of it, but its from like the corner back, maybe a few centimeters cut. He can't fly for some reason...So I need help on what to do. My boyfriend says hes a mallard because he has a green head...I really don't know. I don't want to put him outside because I know he'll get eaten