Eveyone can disagree with me, but to me : parents = worry/orerract.
And it’s normal, us children, can’t really understand before we have some on our own, but when you have to raise a new life, it’s a lot of pressure, you try to do your best and when they feel that bad and have to go to such lenght to ease their pains, a part of you think it’s somehow your fault, or you haven’t done enought.
So it’s your story, it’s your words and I don’t know your parents’ personalities and if maybe they won’t overreacted for sure but all I can give you for good advice is : be sincere. When I had to come clean the first time, it was hard, it was awfull, I couldn’t tell the truth but in that case you’re not allowing yourself to heal. They will want to help them to stop cutting if they learn about that that’s for sure, so be honest with them : when, why and how did you start cutting …
Depending on your relationship and personality, they can go to drastic measures and hide everything triggering from you …. But watever sometimes, it’s for the best.
So yeah, just write that note to explain how you feel , with your true feelings and hopefully, they’d be able to understand them and help you.
Please stay strong <3