Self destructive lies and sneaky behaviour

[Tminus]

Im going through a difficult situation with 15yo daughter recently discovered she had a secret phone after having hers confiscated for innappropriate sexualised behaviour, she has been using this phone to set up social media accounts from which she has messaged a number of classmates we discussed the contents of the messages with her head of year who after meeting with a safeguarding officer decided the other parents should be informed of the messages the school advised we take her to gp as this issue has been ongoing on and off with various boys for a couple of years gp advised a local kids charity whom have spoken with her twice now the second being today she was asked to fill in a form about how she feels aboit herself and her situation one of the questions was aboit self harm and suicidal thoughts neither of which she has ever had or expressed however tonight she has gone into my room and taken her phone back hidden it and ive just caught her using it at 1.30am, obviously o played war said once again she has proved she cannot be trusted and once the conversation was over i went downstairs and she came oit of her room 5 minutes later shouting for help she had tied a scarf around her neck and couldnt loosen it she consistently lies and steals and now with this added into the mix i feel like im at my wits end any advice would be appreciated!

What was the inappropriate sexualised behaviour?
I know it's controversial but I was having consensual sexual physical interactions at 14 and I lived on my own at 16. I would be mortified if my Mum had read sexual messages and then shared them with the teacher and then with other people? Is anyone on this poor girls side? Ridicule and embarrassment are a bad mixture for an already depressed and isolated young woman.

It's awfully to hear of her talking about self harm and suicide. It sounds like she's going through a lot. Had anything happened to her or any changes in her life during the time her behaviour changed? Does she get enough support at home, a good support network of people she can trust? Sounds like she needs to see a counsellor, sounds like a lot is going on in her head, not a very nice frame of mind to be in for her.

I understand this is difficult as stressful for you as her parent too, but remember all you can do is support her, make her feel secure and that she can trust you. And be patient with her. Don't judge her or condemn her for being a teenager and having sexual urges as every single teenager does. Shame and guilt will not help

She was offerring oral sex to a boy in exchange for updating her phone, also the reason i reported it to school was she was talking to one of them about his genitals and he said they did something he didnt want to do and that she had kind of forced him into it and brain washed him and he was uncomfortable, the general tone of messages was her being forceful with them trying to engage in dirty talk and they were either ignoring her or saying they werent interested, if i had seen those messages as her on the receiving end i would have reported the other party, she was also registered as an 18 year old on a various dating and chat sites one in particular called shagastranger.com so woth this in mind and her saftey priority i sought help from school, there has never been any threats or suspicion of self harm before and she certainly isnt depressed far from it shes actually revelling in the situation. She finds it easier or more fun to tell lies its like a challenge and she has admitted the only time she is remorseful is when she gets caught out, she has stolen belongings and money from myself my partner and my business, we have tried to be as supportive and understanding personally i took the softer support her and be understanding approach for the last two years and its just made things worse