expression
cannot suppress one's emotions; cannot help but feel
Used with emotion nouns like 感謝, 同情, 喜び, 悲しみ, often in the pattern ~に堪えない to express an overwhelming feeling one cannot hold back.
See also: 堪える
皆様のご親切に感謝の念に堪えません。
I am overwhelmed with gratitude for everyone's kindness.
彼の不幸な話を聞いて、同情に堪えなかった。
Hearing his unfortunate story, I couldn't help but feel sympathy.
expression
cannot bear the responsibility; unable to cope with one's duties
Used with nouns like 責任, 重責, 任務, often in the pattern ~に堪えない to express that the responsibility is too heavy to handle.
その重責に堪えかねて、彼は辞任した。
Unable to bear the heavy responsibility, he resigned.
この大役は私にはとても堪えられません。
I simply cannot cope with such an important role.