My 6 month old has a cough and is so hoarse :( I've tried vapor rubs, baths, Tylenol (all the meds along those lines),…

My 6 month old has a cough and is so hoarse :( I've tried vapor rubs, baths, Tylenol (all the meds along those lines), humidifier. He hardly eats and sleeps cause he's so uncomfortable. Help! What are your other remedies?! We went to the doc yesterday and they told me to wait it out...