bù​zhī​suǒ​cuò

bewildered

不知所措 bù​zhī​suǒ​cuò
bewildered idiom
not knowing what to do or being at one's wits' end when facing a sudden or difficult situation

The sudden change left him at a complete loss for what to do.

flustered idiom
at a complete loss or feeling embarrassed and socially awkward

He felt a bit overwhelmed by the praise from everyone.

Frequency

Movie subtitles
5.19 per million appears in 3% of films
Written text
5.21 per million

Sources

Definitions
CC-CEDICT