My heart sank when I saw how much work there was left.

我看到还有那么多活没干时，心顿时沉了下去。

《牛津词典》

My heart sank because I thought he was going to dump me for another girl.

我的心情沮丧，因为我认为他要把我甩了，去追求另一个姑娘。

《柯林斯英汉双解大词典》

My heart sank when the man at the immigration counter gestured to the back room.

当移民柜台的男士向后面的房间示意时，我的心沉了下去。

youdao

My heart sank as I remembered that the run-flat technology claimed to eliminate the need for a spare.

FORBES: Measuring the Distance Between a Brand Promise and a Brand Experience

As we turned into a huge parking lot, my heart sank rows of tour buses were discharging Chinese tourists who had also come to see the spectacle.

WSJ: Cormorant Fishing in Yunnan Province, China

Cousy walked onto the court, and my heart sank.

NEWYORKER: Glory Days