I adopted a 3mo old mixed puppy from a shelter yesterday - he seemed very shy at the shelter, but at home he is actually seeming quite depressed. He won't make eye contact with me or my 12yo son, he will not wag his tail, he does not do anything but hide in his crate. He played with a dog, but will not interact with people at all. Will he grow out of this or is he a lost cause? Help.