How abot "to grasp the nettle"?
Don't run around sayin that in the USA, though. Aint nobody ever heard of it.
A similar expression the the US might be to "bite the bullet."
Before anesthesia was available, before a guy was about to be "operated on," he would stick a bullet between his teeth to clamp down on and thereby avoid the distraction of excruciating screams of pain.
Of course ya would always drink about a fifth of hard liquor first, too.
Example: I have no choice but to bite the bullet (and let it happen).