Dear mothers, I have a question. A week ago, one of the baby's nipples…

Dear mothers, I have a question. A week ago, one of the baby's nipples increased in size, and there was also a feeling that fluid had accumulated. We went to see a pediatrician who said it is normal, that this is neonatal mastitis that passes itself. The baby is not bothered by it, but honestly, it really bothers me. Has anyone encountered such a situation? What did they do?