i think i am going insane

im only in my early teen years yet my mental maturity is past all of my peers. im not intellectually superior or smarter but its like talking to a toddler? I grew up online talking to people as old as 16-17 on platforms as I moved a lot as a child and I was isolated. when I was little we had a friend and we were looking for houses since we had just moved to a new country, I was sitting on his lap in the car and he was rubbing and pinching my nipples, i was only 7-8 so there wasnt anything there really but I still dont know if it was okay or not? I dont know if it wasnt  anything wrong and im just so unstable im victimizing myself. I am so empty to the point where im hypersexual and i crave validation from older guys online, it is literally the only thing that makes me feel something anymore. I go to therapy, I have tried getting help, i want nothing more than to disappear and im so numb sometimes i feel like i dont actually value anyone or anything simply because i am overwhelmed with this exhuasting feeling, whenever I have breakdowns my mother insists its my selftalk but i am literally not saying anything in my brain. i feel insane, i will be fine one moment and be so upset the next im trying to hurt myself or self sabotage, i purposely ruin things with people i care about, i purposely tear my nails because I know i feel horrible when theyre short. my therapist says im deppressed but my mother wont let me get an actual diagnosis. i dont even know what im doing on reddit i just need to tell someone atleast an eigth of what im thinking about. certain feelings become unbearable, im always mad, i get so frustrated, i have no patience, I can be happy all day at school then come home and stare at the ceiling for hours,  i hate breaks because of the extreme anxiety I get coming back to school, its unbearable, i hate school because of the pressure it adds to my day, how can I cope? or how can i start being better?