Keep your cool and avoid her. You can do this. I knew I could still sit my N.E.W.T. exams with the Ministry, but it was a point of pride that I complete the year at Hogwarts. I stayed in my room and revised, and snuck down to the kitchens to get some food that evening. Ginny floo-called me that evening, and immediately after she heard what had happened came through the fireplace to console me.