本是凉薄之人怎能温暖他人
[bĕn shì liáng bó zhī rén zĕn néng wēn nuăn tā rén]
'Being a callous/cold-hearted person myself, how could I ever warm up anyone else?' Conveys the idea of someone acknowledging their emotional coldness and doubting their capability to care for or affect others positively.