Thank you so much, his vomiting has subsided, so hopefully he is on the road to recovery.
Right, don't try to make him eat. Just let him drink small amounts at a time. If you have pedialite, give him some of that, otherwise water with a tiny, *tiny* pinch of salt and some honey or maple syrup. That will help to keep his fluid and electrolyte balance up a bit. But plain water will do.
Keep a very close eye on him. If you see any signs at all of any deterioration, take him either to the emergency clinic, or to the vet's emergency facility. There usually is one if you call your vet out-of-hours, they will often leave an answerphone message with an emergency on-call vet to ring if needed.
If he keeps vomiting or the diarrhea gets bad, he does need emergency care, simply because his water intake will not keep up with his dehydration risk. A tiny dog is at greater risk too.
If he stabilizes, and there is no more vomiting etc, then just fast him completely for 24 hours with just water, then try him again with plain boiled rice, then if he keeps that down and seems hungry, gradually start mixing some plain boiled white fish or chicken breast in with the rice. Very gradually introducing his regular food over the further few days. Hopefully he has a simple tummy upset or a reaction to something he ate perhaps