Take him to the vet!
If that's not an option, keep him comfortable and in familiar surroundings. Labored breathing may suggest stress and/or a fever. Panting is the only way, aside from the pads of the foot from which sweat is secreted, for dogs to release heat. Try to eliminate or reduce any sources of stress. If you feel you can do so safely, you may want to take your dog's temperature rectally. If it is above 103 F or below 100 F, you should seek veterinary care.
It sounds like he's in a rough place. I wouldn't wait more than three or four days to see if his health improves before getting professional help.
If that's not an option, keep him comfortable and in familiar surroundings. Labored breathing may suggest stress and/or a fever. Panting is the only way, aside from the pads of the foot from which sweat is secreted, for dogs to release heat. Try to eliminate or reduce any sources of stress. If you feel you can do so safely, you may want to take your dog's temperature rectally. If it is above 103 F or below 100 F, you should seek veterinary care.
It sounds like he's in a rough place. I wouldn't wait more than three or four days to see if his health improves before getting professional help.