I compliment you for having the heart to help the puppy. Unfortunately you don't have the knowledge to take care of a sick puppy. You gave the puppy cow's milk which he cannot absorb because dogs cannot tolerate lactose in cow's milk. They can only absorb dog's milk and goat's milk. You should have brought the puppy to see a veterinary doctor as soon as you got the puppy to have a complete evaluation of his health situation and you should ask the doctor all the questions on how to take care of the puppy and what to feed him. Good luck next time.