Hello everyone, my son got sick right on his birthday. He had a fever …

Hello everyone, my son got sick right on his birthday. He had a fever for a couple of days and then runny nose for three days. On the third day, he developed a terrible cough at night, it was terrifying. It seems like he's struggling to breathe all night. I stayed with him, didn't sleep. We went to the hospital and they said it's laringitis. They prescribed injections, ointments, syrup, and drops Fenistil for allergies. So much! It's awful. I'm just worried because he's so small and there's so much more. They said we should avoid sweets like yogurt and cookies for a couple of months. Can anyone tell me how quickly their