She lives in filth, does not sleep, does not go to school, eats at all hours, and cannot concentrate.
All teens TRY to live in filth, this is the one thing you can definitely change (clean her room, but her nice stuff for a shower!!)
School avoidance is huge at the moment, we had a nightmare (the worst, called in by school etc etc) of a year last year with my son literally just saying‘I’m not going’ and us constantly having to (try to) talk him/ bribe him etc.
All teens also eat all hours (who cares really, just laugh roll your eyes and try to get a bit of change or get some healthy options in there)
and she has adhd so your thing with concentrating is to try to help her, if she’s on screens a lot uou try to help her off them, ds was ADDICTED (so to the point of blinking eyes, not sleeping, suddenly staring into space if we were talking to him).
To help him off I’d ask him for help with random tiny things, myself or dh would just chat to him over something he had an interest in, we literally nearly took him back to toddler territory- we’re baking, can you help with the dishes, we’re playing a board game, if you play we’ll get x or y, or we’re going for a family walk or the dog needs company god poor dog must hate us.
You keep saying you’re a professional and I think you’re in the ‘how can this be happening to us’ stage. We had no drugs or sex stuff but we were also blinded by the ‘we do everything right, we’ve gone about everything the right way and given them all they need how can he suddenly not be going to school/ staying up all night/ telling us to fuck off, slamming the door, shouting etc etc?’ You need to forget that and figure out when she changed and get back to having a daughter. Unless she’s evil (I mean film evil!!) chances are she feels out of control and would welcome help.
The untidy room (which you and dh can fix), smoking, eating etc isn’t something that harms your family really, the being angry, the arguing, shouting and the sex is so there’s where you need to start. Try to talk and if she doesn’t listen make her some of her favourite food and leave her to it. Maybe try the next day. No blame, no questions just ‘god it’s awful weather’ or ‘oh my god remember this (random thing in her room). Buy her a bloody care bear or something that reminds her she’s a human child!!!!!!
And consider moving and commuting, working less (same with your dh). Break down the problem and work on it. No matter what goes on in our house at least now our son chats to us, laughs with us and is relaxed and the others now aren’t nervous of him. We have our little boy back. You can get your little girl back