你离开我比世界末日更可怕
[nĭ lí kāi wŏ bĭ shì jiè mò rì gèng kĕ pà]
This nickname expresses deep emotional pain and fear of being left alone, suggesting that the prospect of a loved one leaving is even more terrifying than the end of the world. It's a very dramatic way to describe intense feelings of insecurity and dependence in a relationship.