Ask your vet about using Zantac for the nausea, they will need to give you the correct dosage based on weight. When Duffy was in the e-vet this is what they used with good results.
Is Smokey usually a hairball thrower? Is is possible he still has some hair left that needs to come out? If so you can give him a 1/4 tsp of butter to lick, that will help smooth things out, may get him interested in food again too.
What are his poops like right now? Okay or dry?
Duffy would vomit abit of white foam when she was trying to pass a particularily dry poop or if she went too long with nothing in her stomach so I made sure she had a snack at bedtime.
Sounds like he's running/hiding from you right now cuz you keep giving him the yucky tasting stuff
You can try a 1/4 teaspoon of Slippery Elm Bark powder in his food, just be sure to mix in a teaspoon or 2 of water in as well This will also coat the stomach & intestinal tract, he may respond better to the flavour of it.
Have you tried bit of parmesan cheese, pinch catnip, warming the food, bits of roast or bbq chicken, crushed treat, dab of melted butter on top?
I would give the fluids early if you think he needs it, there is no rule that says the schedule can't be altered if need be.