bang one's head against a wall["불가능한 일을 시도하다, 계란으로 바위치기"]

bang one's head against a wall

: to try to do something without success 

   "불가능한 일을 시도하다, 계란으로 바위치기"

: bang 대신 knock을 써도 됨.

A.

I've been trying to get a job for six months.

I've mailed a hundred applications.

I'm doing everything possible, but I still can't get a job.

I'm just banging my head against a wall.
B.

I've been working on an assignment for my teacher for three days now.

I feel like I'm banging my head against a wall.

I can't think of anything to write.

[주] 

: applications : 입사 지원서