Being sad is one of our emotions. The degree of sadness can be different. These five set phrases have the strongest degree for sadness.
痛不欲生 [tòng bú yù shēng] be overwhelmed with sorrow
的丈夫去世后，她痛不欲生。
She cried her heart out after her husband had passed away.
心如刀割 [xīn rú dāo gē] feel as if a knife were piercing one’s hear
他走了以后，她一直坐在家里，心如刀割。
Since he left, she’s been sitting at home eating her heart out.
肝肠寸断[gān cháng cùn duàn] overwhelmed by grief; sorrow-stricken
他妻子逝世使他肝肠寸断。
The death of his wife broke him completely.
悲痛欲绝[bēi tòng yù jué] be extremely grieved
听到儿子在事故中丧生的消息，他悲痛欲绝。
With grief at the news of his son’s death in an accident.
悲不自胜[bēi bú zì shèng] be overcome with grief
我相信她比我还悲不自胜。
I believe her heart broke even more deeply than mine.