What Causes Headache,vomiting And Black Line Across Vision?

Hello. Few weeks ago in the morning I had a black line across my vision with my right eye and I could not see the part that has been covered with the black line. About half an hour later, I had extremely bad headache on my left and right sides of the head and felt sick. Soon I eventually puked. As I was in school that morning I was not able to take any medicine so I was sent to the medical room see the school nurse and rest. Approximately an hour later the headache eased. This is not the first time this happened - It started happening about 3 years ago, but it was not as bad as this.