desperate for help!!! I haven't had any sleep due to my 9 month old being sick. he has a really bad…

desperate for help!!! I haven't had any sleep due to my 9 month old being sick. he has a really bad cough. he's went to the doctors and been tested negative for everything. RSV, whooping cough, pneumonia, the flu. but his doctor said its just a virus that he'll have to fight. No medicine is helping either. I have a humidifier that goes at night. the heat on he gets cough syrup every 4 to 6 hours. Vick's on his chest, back, feet, and nose ( doctor said all areas were fine to put Vick's) so help. what am I doing wrong??? he's seems to not be getting any better. he's not getting any worse so that's a good thing.