Praying your little one feels better soon
From what you are writing it seems the vet has it under control.
Just remember, he is pretty tiny and is very young for the most part they do have sugar issues which you need to monitor by keeping him fed -even if it means opening their tiny mouth and putting something on their tongue.
I think a lot of members can have excellent input on this subject, I have even read some giving the little ones baby food.
Hopefully others will respond soon.
Keep the faith, everything will turn out well.
Bless