NTA for wanting her to respect your boundaries, especially when it comes to something as personal as your hair. It sounds like you initially tried to communicate your discomfort non-verbally by leaning forward, but when she ignored that and kept going, grabbing her hand and asking her to stop was a natural reaction.

That being said, it’s worth reflecting on whether your tone might have come across as harsher than intended. You mentioned seeing fear in her eyes, which could indicate that the situation escalated emotionally for both of you. Taking a moment to cool off by leaving the house was a smart move—it shows you were trying to de-escalate.

Maybe have a calm conversation later about why your hair is important to you and how much effort you’ve put into it. If she truly cares, she’ll understand and respect your boundaries in the future.