Number one is to address the tail issue, feeding can wait, depending on the severity a vet will be required, in the meantime make sure that the animal is placed on a clean and dry substrate (Paper towel) and remain clean. You can clean the area with betadine (that's it at this point since I have no idea of the damage.

Feeding will take several step

#1 Getting the animal to eat for you which will likely mean feeding what was fed previously. Once your BP eats with consistency (3 to 5 feeding) trying switching.

#2 Switching, switching is a one step at the time operation from live to f/T or from one prey type to another and then the next step, this makes the transition a little easier.

Trying to switch from live mice to f/t rat could be very difficult, I would personally go from live mice to F/T mice and once the animal eats with consistency go from f/t mice to f/t rats using the f/t mice at first to scent the f/t rats.

And remember switching requires tough love and of course this means the animal should be healthy and of a good body weight.