Taking bactrim (sulfamethoxazole and trimethoprim) and flagyl for diverticulitis. horrible nasuea, headache and chest discomfort, body aches and just feel sick. should i stop the med?

No: While nausea is a common adverse effect of almost any medication, the other symptoms you describe are not likely to be caused by these antibiotics. They could be caused by worsening infection, but an exam is necessary to make that determination. Seeing a doctor (preferably the prescribing doc) without delay is important in this situation.