your ex sounds like he is pretty set on his thoughts, the big thing to remember is he cant really help it, its his mind, paranoia, and actions put all together, and those people in the hospital are always repetative, i have "psychosis" but idk, alls i know is delusions can COMPLETELY alter what really is happening, and you have no way to control it, so maybe descretely you can pull him back to reality, but not in a way that would make him think you were against him bc that would just push him away quickly. hope i could be of some help, if you have any other questions feel free to pm me best of wishes to you and your ex