I hope he is going to be okay, may have just caught a bug and not feeling himself. If this continues, keep a close eye on him, call a pet shot. Many own dogs and may offer help or if you can afford contact vet. For now, just wait and see. I pray he will be okay
A fever is not a good sign it is a sign of infection or worse especially with vomiting and diarrhea, I'd get him to a vet ASAP for proper diagnosis and treatment. Best wishes.