My son was an absolute nightmare between the ages of 11-14. He was permanently excluded from school last year and ended up in alternative provision until the Covid19 lockdown put a stop to all of his support/education.
I had been fighting for years to get him help, from when he started at secondary school. I knew there was something that was being missed. He was cutting (self harming), threatening suicide, getting into fights, being combative at school, getting into trouble with the police, stealing, the list goes on. My DS could start an argument in an empty phone box, particularly if he thinks he is in the right. I was receiving phone calls from school almost every day about his behaviour.
But I knew my child and I also knew that he needed help. So after almost four years of stress and taking him to CAMHS and his GP and talking to the school and being on a waiting list for almost two years, I finally got him an appointment in December 2019 with two NHS clinical psychologists who diagnosed ASD (Aspergers).
They basically said he cannot cope with "normal life" in the same way as other people. Almost everything confuses him and stresses him out.
He moved in with his dad two years ago (he will be 16 next month) and whilst this broke my heart at the time, I knew that I could not emotionally cope with any further stress, as a result of his aggressive behaviour and him smoking weed and drinking at 11 and 12 years old.
The diagnosis seems to have flipped a switch in his head and all of the aggressive and anti social behaviour has stopped. He has stopped smoking weed as well, as he says he feels better without it.
He has told me that he always felt that something was "wrong" with him. He said that he knew he was different from his friends and at times he felt suicidal. The knowledge that there is a reason for him feeling different, an actual reason diagnosed by a doctor, makes him feel much better about himself and he has sorted his life out and is going to college in September (hopefully!).
What I am saying OP is that my DS's behaviour over that four year period nearly drove me to a breakdown. I was absolutely at the end of my tether. But if he wanted to come home then I need to judge him as he is now, not how he was when he was 14. Only you can decide whether he has changed enough to let him into your home again, but I would suggest that your relationship with him might be improved by giving him the opportunity to show you that he has grown up.