Hello My Wife Is Experiencing Fatigue, Loss Of Appetite, Fever,

hello my wife is experiencing fatigue, loss of appetite, fever, body aches, severe cough, burning watery eyes, and diarrhea. she has seen a doctor about four days ago but her symptoms have not changed. they told her that she had a sinusitis. but the medication she is taking has not worked they prescribed her an amoxicillin 500 mg. can this possibly be anything else besides what they diagnosed her with?