Am i overreacting or right?

So some details to this Situation.. I (nb 15) have a lot of Problems with my parents... They force me to strip naked to they can search for Sh wounds.. And when they find some they slap and kick me with the Motto "if u hurt urself this should be no issue" sooo since i ran away my parents have been rly nice and quiet because the Police supects abuse... My mom runs and walks behind me all the time.. I can't go to the toilet alone because she will wait infront of the door making sure u dont do anything... She asks me annoying questions every day and she always says to me that im lying... With everything... I had a workshop today at school and she called my school telling me that im lying even tho 4 whole teachers confirmed that i was there the whole time... Every time i get annoyed and just raise my voice a bit its always the same thing... Im not good in ma head and i should go away and im a mistake and i should kms and i should cvt deeper till i bleed to death because thats what everybody wants bla bla bla always the same... And After getting to hear the same thing for the third time this day every day straight i snap... I yelled at her in a annoying tone that she should leave me alone and that i only want some privacy and stuff and Just dont want her to watch EVERYTHING I do... Ofc i got a slap across my face following with telling whilst im sitting on the ground in the corner collecting kicks and slap from my parents... Its almost normal for me and i dont know what to do... Police and Child Services dont want to help me because i only do it because of attention... the parents of my friends AND my friends dont believe me because when they are over at my house they dont See anything till they leave the room... Only once a friend has walked hin on my parents beating me up whilst she was over :/... I dunno what to do anymore... I feel like there is no solution for this and im Stück in a maze... I rly need help