baby has bronchitis ... has anybody else went through this

So I took my 5 month old to the er on Wednesday at 12 am because he couldn't breath and had a high temp it's now Saturday and still has high fevers his white cell blood counts are 21,000 so there a infection somewhere and we still haven't been able to figure out where it's coming from cuz all the blood work comes back normal they say he might get to go home tomorrow if the can find the infection and start treatment but as of right now they have 0 clue where the infection is coming from he's on iv fluids because everytime he eats he throws it all up he's doin a little bit better today but he was like that yesterday and once the Motrin wore off he spiked a 101.8 fever again I'm staying hopefull but I'm so scared at the same time cuz every time I pick him up he starts screaming so I haven't really been able to hold him