2007 Dodge Charger Highway accident

Hello, Last night we were driving on the highway at about 70-75 mph. A cat was on the road and didnt see it on time my friend ran it over. We thought nothing of it until we pulled over and my brother noticed the car was leaking. He just put some antifreeze and water in it. Also there wasnt any oil in the car so he put some of that in there. We drove fro about 2-3hrs stopping every 30-45 min to add more water, because it would heat up? The last time stopping the car stopped steering completly shut off? Is this just the radiator or the hole engine has to be replaced since it completly died on me? Is it worth fixing?
-LC