So I brought my baby to the doctor Friday for his finger being bright red and puss coming out. They…

So I brought my baby to the doctor Friday for his finger being bright red and puss coming out. They said nail bed infection and put him on antibiotics. He has been miserable since. He has this horrible green diarrhea. He keeps throwing up after nursing which he never did. And screams with gas. I feel like antibiotics are too harsh on his 3 month old system. Ugh. Still 5 days of it. And his finger looked totally fine by the next day ugh. Anybody ever have this happen with meds on a small baby