I went to teach diabolo

Today I went to teach diabolo, and I told my student to pay attention to me. But they didn't listen to me, so I use my diabolo stick to hit them, and one of my student it's a girl and she cry because I hit her, at that moment I was shock. Because I think I hit very softly I didn't hit very hard. And the teacher go to consoation her. Then I said sorry to her and she didn't forgive me, so I am so sad.