Girls, hi! What can I give a 4-month-old baby? We have a wet cough and…

Girls, hi! What can I give a 4-month-old baby? We have a wet cough and phlegm. The doctor just said to rinse his nose with aquamaris. Today she looked in his throat, it's red, now we rinse with aquamaris, aspirator removes phlegm and throat, but only started applying interferon ointment. Wanted to go back to the doctor today so that he could properly examine him, and prescribed normal treatment, booked for 2:00 pm, went there, they say the appointment is at 4:00 pm ??‍♀️