If the pup is hypoglycemic (and it sounds that way), then him running around too much can cause it to flare up again. He needs to be kept quiet so he can conserve energy, he cannot afford to be burning up all those calories right now
Do you have a pen you can keep him in, so that he can still play a little bit without all the full-out running?
Keeping him warm is important too, as it takes a lot of his energy to keep his body temp up where it should be. Feel the tips of his ears, if they feel cold then hold him against your body for warmth, or make him a sweater from a sock. I went through all this with my Luna when she was a baby, and we almost lost her
If he's still vomiting at ALL, get him to the vet asap.
