How do I tell my therapist about my addiction to porn/will she tell my parents?

I'm a minor, female at birth, my mother used to have sex in the same house and I could hear, I was groomed, I got unrestricted access to the internet and that's of course where it all starts. I would like to tell her but I am afraid of her telling me that my parents should know, as my mother was one of the reasons and i already know she will do nothing to help just like when I told her about my self harm addiction, I also do not like crying infront of people and haven't infront of this therapist but I know if I try to bring it up I will begin to cry and I'll feel judging no matter what reassurance is given. I also unfortunately this is a very teenager thing to say, am scared of her telling me too just not use my phone ever, despite the fact that it is where I get it, the reason I'm typing this up is because of how just hours ago it got very bad and only because I looked at a relationship I had a long time ago (ik I shouldn't be dating at my age it wasn't something that I wanted to be in) which sexual themes was pillar in that relationship. Since then I have been clean since! My devices (again I get how corny this is) are my escape, my mother and I will never see eye to eye, my father is not in the picture and that may be a factor, we do not have the money for outdoor activities that would take my mind off it so if my devices were taken away I would be sleeping all day everyday. This is also a topic brought up because I am going into a public school after recently being in a private school and homeschooled and this may be an overreaction but I fear I may be easily tricked into having intercourse with someone, also not something I want tho if I'm addicted to porn you can see how that could make me susceptible to such things. And my mother does not support abortion.