It's possible that the girl is angry not because she was romantically interested in you, but rather because she valued your friendship and feels hurt or confused by your sudden withdrawal. When you stop talking to someone with whom you had a friendly relationship, it can be hurtful and leave the other person wondering what they might have done wrong.
Here are a few potential reasons why she might be angry or upset:
Emotional investment: Even if she wasn't romantically interested, she might have invested time and effort in building a friendship with you. Your sudden withdrawal could feel like a rejection, leading to hurt feelings.
Lack of communication: If you didn't explain your reasons for stopping communication, she may be feeling confused and left in the dark, which can be frustrating and upsetting.
Changed dynamics: Your sudden change in behavior might have disrupted the dynamics of your social group or shared activities, making her feel uncomfortable or excluded.
Unresolved issues: There might have been some underlying issues or conflicts that were not directly related to romantic interest but were still significant enough to impact the friendship.
Feeling ghosted: When someone stops talking to another person without explanation, it can feel like ghosting, which can be hurtful and disrespectful.
It's essential to remember that friendships are valuable and meaningful connections too, and just because someone isn't romantically interested doesn't mean they can't be hurt or upset by the way you handle the situation.
If you value the friendship, it's best to address the situation openly and honestly. Talk to her, explain your reasons for withdrawing, and apologize if your actions have caused her any pain. Open communication can help clear up misunderstandings and potentially salvage the friendship. However, it's also essential to respect her feelings and give her space if she needs it.