YOU SAID:

I fell stupid for getting a d on my exam last week

INTO JAPANESE

私は先週私の試験に広告を出したことにバカになった

BACK INTO ENGLISH

I became stupid to advertise in my exam last week

INTO JAPANESE

私は先週私の試験で宣伝するのが愚かになりました

BACK INTO ENGLISH

I became stupid to advertise in my exam last week