The outcome is sad, but it seems to be unavoidable. You describe well your efforts to repair the friendship many times, but Star's response was not rational. She apparently had issues that were personal and somehow related to exam taking. Whether that meant she was jealous, or merely stressed, didn't matter. This was not an issue you could affect with your behavior.
Good use of dialog in this piece, @loveth97.
Thank you for sharing this experience with us.