I Became the Fiancé of a Dragon in Romance Fantasy

In a world where selfishness was the norm, did a rare few people show kindness because of their upbringing? Was one's personality determined by the environment or... were humans inherently evil? I had such questions when I met a child who gifted me a novel showing the struggle of a kind dragon princess in an unforgiving world. But I didn't find the answers to these questions no matter how hard I tried, until ... I reincarnated in the novel as a dragon’s fiancé and found out my marriage was soon to be broken.