Side effects to Zofran?

My babe is two weeks old and I’m taking antibiotics to prevent infection from a bad tear. The doctor prescribed Zofran to counteract the nausea caused by the antibiotic Bactrim. I still feel terrible every day for at least several hours, extreme fatigue, nausea, stomach pain, headache, loss of appetite, etc, and assumed it was related to the antibiotic. Is it possible the Zofran is causing these symptoms? Has anyone had this issue with Zofran?