I did this when I was 7, and I cut my bangs. I lied and said someone in my class had cut it (I was in Public School at this time), but years later I told my mum the truth. Oh... I was punished really bad for that. Just tell your mom the truth and then tell her your feelings and how you are being bullied. My mum wants me to do certain things and I tell her about it and she'll usually understand and say, "You should've told me you felt that way!" Good luck!