我不孤单不难过你不用担心
[wŏ bù gū dān bù nán guò nĭ bù yòng dān xīn]
Means 'I'm not lonely, I'm not sad, so you don't need to worry'. This could reflect self-reliance, trying to assure someone (perhaps a loved one) that despite their concerns, everything is fine emotionally.