DS1 is 16 year old, has ADHD and his behaviour is absolutely horrendous. He has generally always been bad but the last few years have been particularly awful and now he is at his absolute worse. He was asked to leave his original independent school in year 8 for poor behaviour, got excluded from a state secondary at the beginning of year 10 for bringing edibles into school, had a failed managed move then (after a massive battle on my part including getting him an EHCP) joined another school in March of year 10 and stayed there for his GCSEs. He managed to get 965555544 in his GCSEs but only because I got him tutors in literally every subject and we had massive arguments every day because he didn't want to do them (although he did eventually after keeping them waiting for the first 20 minutes of every 1 hour session). Can't tell you the amount of money spent/wasted and the stress involved.
So, he is now at sixth form doing 3 A-levels but has very little motivation. His attendance is 65% - no matter how many times I tell him to go school in the morning, he refuses, mocks my voices, swears at me (f-off), slams the door in my face etc. Makes absolutely no difference. He goes in at least an hour late each day, skips lessons, then comes home around 3pm, sleeps until 8pm, goes out to play basketball and then comes back around 11pm. He is then generally up until 3am (refuses to go to bed), being really loud (bouncing his basketball in the lounge so the whole house shakes (we're in a terraced house so the neighbours also complain), cooking noodles and making a massive mess for me to clean up in the morning. He rarely if ever speaks to me and if he does it's generally to be rude. He also smoke cannabis fairly regularly, including in his room, and won't stop when I tell him to. Literally nothing works with him. I am divorced from his dad who also seems to have no influence over his behaviour - he refused to go and stay with him and I can't physically make him. He also hates his stepdad.
Does anyone have any advice on what the hell to do?