Have you been documenting each incident in detail as it happens? You should. Keep an initialed, dated “log” of the events. This way if (when, IMO) you need to acquire a protective order against him you have that to back you up. Your top priorities should be staying alive/sane, and protecting your younger son. I wouldn’t let him move back in with me, maybe never. (Unless he’d been sober for years, and had made astounding progress as far as growth and taking responsibility for his life.) Maybe you should go to a counselor who has experience dealing with domestic violence and drug addiction yourself, they could probably advise you how to best proceed wrt your younger son, and help you regain your balance. They could probably also help your younger son realize the implications of his brother’s behaviors, and come to terms with things. I’ll be honest, I fear for the safety of you and yours. Take care, please?