You should've been more understanding. Both the two of you are still in school so it's really important to stay on the right track and focus on school. And she is really busy, just because she don't have the time to pay attention to you, you shouldn't done what you did. I understand you were insecure and worry and just want to make sure things are still going on between the two of you but the best thing is to listen to her and believe her. But know what if you still have feelings for her, go for it! believe ur feelings and this time just be more mature and understanding. And if she don't care for you anymore, you have nothing to lose, at least you give your feelings another chance.