break your neck

break (one's) neck

To put forth a great deal of effort. I've been breaking my neck trying to get a passing grade this semester, so failing by two measly points is incredibly frustrating. Don't break your neck trying to please these people—they'll never appreciate it.
See also: break, neck
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

break your ˈneck (doing something/to do something)

(informal) make a great effort: There’s no need to break your neck trying to get here by five. We can always wait for you.
See also: break, neck
Farlex Partner Idioms Dictionary © Farlex 2017
See also:
References in classic literature ?
'And I pray that he may break your neck: take him, and he damned, you beggarly interloper!
Do you want to run away, you ferocious beast, and break your neck?" when all the time the horse was not doing anything in the world, and only looked like he wanted to lean up against something and think.
`My wife said, `If you break your neck again, you're calling your own ambulance,' ' Tinsley said, his eyes watering with laughter.
'I'll break your neck and his bloody arm,' he told Emu.
If you break your neck as high up as that, there's a fair chance it kills you."
It's bad timing, but when is a good time to break your neck?"