Can I write my essay about this?

the admissions officer is not a psychologist. If you’re going to talk about a traumatic experience, talk about how it broke you but how you survived and how it’s changed you now, what you learned from it, what you want to do with your life about it. If you’ve read “Before I fall”… it’d have to be a 600 word transformation like that.
In addition, you really need to show the paper to 3-4 people before you submit it so that you can refine it.
There is confidentiality, your parents will not see it, but you really have to be careful that you don’t come off as whiny, or mentally disturbed, or too graphic. In this type of essay, suggestion rather than being graphic, is the key.