I tried putting the leash on my puppy (who is 12 weeks old) and he freaked out. He ran away and was whipping his head. I tried tugging it a little to get him to walk towards me but he ran under the table and hid. When I went over to him he had his ears all the way back and looked terrified. He jumped in my lap and sank into me. He is terrified of the leash! What do I do?