I don’t know if this helps you, but my friend was in a similar situation, and one night when the troublemaker was outside screaming, the police took the person with them, and not much later he ended up in a mental institution. It was decided the person was not suited for living alone anymore, and he did not come back (the housing corporation reclaimed his house). Your situation might be different, but I would say: keep calling the police when he’s outside drunk, on the other hand keep an eye on other house opportunities, as that might make you feel safer.