パスポートが見つからなかった時、とてもあせった。

I became very nervous when I couldn't locate my passport.

パスポートが見(み)つからなかった時(とき)、とてもあせった。

Pasupo-to ga mitsukaranakatta toki, totemo asetta.

パスポート (パスポート)

passport

が (が)

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

見つかる (みつかる)

to be found; to be discovered

時 (とき)

time; hour; moment; occasion; case; chance; opportunity; season; the times; the age; the day; tense

迚も (とても、とっても)

very; awfully; exceedingly; (not) at all; by no means; simply (cannot)

褪せる (あせる)

to fade; to discolor; to discolour

Readings: ケン、み.る、み.える、み.せる

Meanings: see, hopes, chances, idea, opinion, look at, visible

Readings: ジ、とき、 -どき

Meanings: time, hour