我有认真说我爱你可你不信
[wŏ yŏu rèn zhēn shuō wŏ ài nĭ kĕ nĭ bù xìn]
Translating to 'I said I love you seriously but you didn’t believe', this expresses frustration and sadness about a sincere confession of love that wasn't believed or appreciated by the other person.