Hello, I Am A 19 Year Old College Student Living

Hello, I am a 19 year old college student living away from home. I went to the doctor and had a sinus infection and I am still taking the amox. twice a day but about every other day or so I still present nausea and little vomiting. I have had this infection for 2 weeks now and now the vomit is mostly just mucus. but when I have a major coughing episode that is when I seem to vomit. what should I do?