I need help with my foster!?

Separate the dog and the puppy often to give the older dog a break. You can start feeding the puppy from your hands. Train him to take the food gently. When he realizes that the food acually comes from a human, many times the food aggression stops. Also feed several meals throughout the day. Keep the other dog away at first while you are doing this. Don't be messing with the dog's bowl all the time. You probably would be offended if someone was putting their hands in your plate or trying to move your dish while you are eating.