Girls, please tell me, we're 4.5 months old, the baby started coughing…

Girls, please tell me, we're 4.5 months old, the baby started coughing, I thought it was because of the saliva, I looked in the throat, and there was a red tonsil on the right, there are no other symptoms, no fever, runny nose, dry cough like it's being choked by saliva. We called the doctor, waiting. Tell me how you treated such tonsillitis? Thanks in advance!