baby not eating at all

my baby has a stuffy nose and a small cough and has not been eating good since 12 am the other night, if he eats he’s eating 1 oz or forcefully 2, i went to the pediatrician and they just told me tylenol and saline drops and i have a humidifier and nothing is helping i’m really worried and wondering if anyone has gone through this? i’m stressing so bad i’ve been crying on and off because i’m not sure what to do now