my pup is sick and I don't know what to do!

I am waiting for the vet to open right now. I called the emergency clinic and they said to take him back to his vet as soon as they open.

We had him nutered yesterday. We picked him up at 4:00pm and the vet said to feed him b/c he didn't have food since 4pm the day before. He said to make sure not to feed him too much at a time otherwise he'll throw up.

Well, yesterday he wasn't interested in food at all. He just drank water. If he did eat anything, he threw up. Even after eating the tiniest amount.

He is still throwing up when he eats, which is not much b/c he has no appitite. He is very listless and not himself at all. He still looks woosy. I can't get intouch with our vet still and I am trying to get intouch with work to tell them that I'll be late. I also can't get intouch with my DH. I am going out of my mind! I'm too scared to leave him!