How to calm you're girlfriend down ?

My girlfriend found out one of her friends she used to roleplay with followed her on her new Instagram account has her blocked on her other one still follows her best friends. It made her really upset when she found out she thought they deleted their account but has her blocked for no damn reason she doesn't understand why these mean people rather follow her friends than her she didn't do anything it makes her upset and depressed now after 2 years they wanna follow her back she doesn't know what to do. She has a bad panic attack last night over it she doesn't understand why people are mean to her for no reason. How can I calm her down ? Why are people on Instagram so mean ?