What's wrong with my dog :(?

It sounds like he may be having separation anxiety. My Shih Tzu Maltese goes periodically to a kennel. He comes back exhausted from the kennel and takes a couple of days to come back to normal. During that time, he is looking for more attention and sleep. However, what helps us is that I take him one or two times to the same place for day care. That way, when I need him to stay, it is not too traumatic for him. Good luck!