YOU SAID:

i was up all night studying for my exam next week

INTO JAPANESE

私は徹夜で勉強私の試験の次の週は

BACK INTO ENGLISH

In the night I was studying my exam next week

INTO JAPANESE

夜に私は私の次の週の試験を勉強していた

BACK INTO ENGLISH

In the evening I was studying my next week's test

INTO JAPANESE

夕方には私は私の次の週のテストを勉強していた

BACK INTO ENGLISH

In the evening I was studying my next week's test