Baby cough for 9 days

My 9 month old has been congested for the last 9 days and it isn’t getting better. He has a cough, runny nose and sometimes his breathing is raspy. I went to the pediatrician yesterday who said his breathing is normal, no ear infection or sore throat. He wants him to get a Covid test and if he doesn’t get better he wants him on antibiotics. I would like to avoid giving him antibiotics if possible. He is still FULL of energy and has a really good appetite. He sleeps through the night but occasionally will have a hard time settling and change position for about 5 minutes. His cough is worse at night. I do run the ac in his room because it’s warm where I live. I’ve been using a humidifier, saline nasal drops, chest rub and a snot sucker. Any natural remedies you tried and swear by?