Someone ratted me out in school

[clean streak of 2 months] Been cutting for not even 3 days, been hiding it well, yet somehow someone found out and told one of my teachers and then that teacher told the school nurse. Like not even the one that's at the front desk of the health offfice. The ligitiment, trained, went to medical school, school nurse. I had to tell my mother and grandmother.I got to get out of the last 3 periods of the day. My mom has threatened that if I do it again, she'll tell my homophobic, "self-harm/suicide is selfish", dad. She wouldn't let me out of her room unless I showed her my arms :(