Regardless of what has constituted your diagnosis and treatment plan, it sounds to me as though little good can come of engaging in detailed conversations about it with your brother in his current state of mind, because he clearly has an agenda that is at least partially imbued with self-serving interests (like wanting you to change your life in a way that causes him not to have to be bothered). Unless he starts singing a different tune, perhaps one about genuine concern for your well-being and of holding a more objective viewpoint about your situation, you might want to suggest he attempt to be more open-minded and less aggressive before he tries to harass you about it again. In my opinion.