kill (oneself) (doing something)

To overexert oneself or overextend one's effort while doing something. Don't kill yourself trying to get the report done tonight—it's not due until next week anyway. They're killing themselves finishing the last touches on the exterior of the house before the storm hits us.

ˈkill yourself doing something

(informal) make a very great effort to do something: It would be good to leave at 7 o’clock, but don’t kill yourself getting here by then. We can leave a bit later if we need to. ♢ I nearly killed myself finishing the report in time for this meeting.