the gal game heroines who avoided the death ending seem to have read my “diary” and discovered my secret

It sounds like you're describing a scenario where the heroines of a gal game avoided a death ending by somehow accessing your “diary” and uncovering a secret you kept hidden. This implies the characters gained insight into your inner thoughts or true feelings, which changed the story's outcome. If you want, I can help you develop this idea further, such as turning it into a short story, dialogue, or game script. Would you like that?