I have pertussis (whooping cough) and after i eat, i start coughing which makes me want to vomit. should i?

Yes: One of the key symptoms of pertussis is episodes of coughing followed by nausea like symptoms and or vomiting. As pertussis is severe infection with lot of mucus body tries to eliminate the mucus by vomiting and if you feels then should vomit. Take adequate rx for pertussis. It may take weeks for symptoms to improve sometimes if infection is severe. F/u with md. Best wishes.