You're spending an awful lot of time and energy trying to figure out what's wrong with him. The DBT workbook did not stop him from being abusive towards you again recently. And now it's escalated to accusing you of abuse and telling his family that you are abusive. Yet there are no repercussions. You are coddling him and you are enabling him. Sorry to be so blunt and straightforward, but you're not drawing the line anywhere. Therefore, there will be no limit to the abuse. He can get away with it with you. And what you're doing is explaining away his behaviors by believing he has brain damage with no proper diagnosis and that he has BPD with no proper diagnosis. You're also continuing to cater to his needs. So what if he feels rejected because you need to withdraw from him when he accuses you of abuse? So what? Let him cry, let him stew. He will continue abusing you because you are allowing it to happen.