My dear, put yourself in the character's shoes. If you defended yourself, it would obviosuly backfire because she is popular. She has friends, and not only that since the posts are now public, that will make her seem more like a criminal. People think the mc bullied when we know it is not true, but again the school believes it is. Respectfully, you wouldn't be able to stand up for yourself either if you were deprived of sleep, affection, and friends.