在你心里我已经不重要了
[zài nĭ xīn lĭ wŏ yĭ jīng bù zhòng yào le]
It means “In your heart, I have become unimportant.” This expresses sadness due to the fact that they believe they no longer matter to someone who is emotionally significant to them. Perhaps it conveys the pain and helplessness after losing something important in a relationship.