also what was the triggers for him to discover the truth when he was starting to get happy and starting to leave all that behind, his cousin came to see him but was his cousin real? that could be the trigger but if he didnt was real than i dont see no reason for him to have this breakdown for no...
what bothers me about this is that it came out of nowhere there were no signs that he was making it all up, sure we only saw the story from his perspective but that is just lazy to solve the manga this way