Hello, Nausea, coughing and throwing up occur due to lack of foreplay and positions that facilitate deeper penetration, aggressive sex, vasovagal response can cause such symptoms. Underlying health conditions like PID, sexual trauma, sexual aversion disorder can also cause such symptoms. Avoid oral sex, you are sensitive, and it will trigger your problems. Get clinically examined and get your underlying health condition treated. Avoid eating before sex. Make sure that you are adequately hydrated with water and fluids so that you are not left fatigued after sex. Take food after resting and relaxing for a while post sex. Prefer to have a longer foreplay and avoid positions that enable deep penetration. Avoid aggressive sex. Consult a psychiatrist. You may need medicines to avoid anxiety and stress. CBT, talk therapy and regular walking and exercises are helpful. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician