I hope he continues to improve... I'm thinking maybe do an xray and have a look... I'm assuming he has not vomited... And , yes, it's very hard to have to leave them in the hospital when they are so young. But it is the best thing to have him getting fluids and food.
If you can't take him to work with you, do you know anyone that could take care of him while you at work? He's really way too young to be left by himself, especially with a tendency to go hypoglycemic (which is normal for younger puppies)... he'll need more frequent feedings and someone checking to be sure he's eating enough...
Praying that all goes well and he makes a speedy recovery...
