Sorry but this is beyond grasping for straws.
I may be reaching for straws, but the tone leads me to think this was a matter of honor or a promise, not some personal duty.
His mind was scrabbling around for straws to clutch.
She was a lost soul, drowning in despair, looking for straws to grasp.
Loss after loss shattered their faith in what they were doing, which brought on more grasping for straws.
It is hot, and we're all tired, and we are grasping for straws in the dark.
I was waiting, you see looking for straws in the wind, I suppose.
I know a lot of folks believe I'm reaching for straws, even some in the ministry.
The pretty copper water goblets were unpleasant to touch; ask for straws.
Finally, grasping for straws, you turn to the shorter, middle story in the volume, "Jealous."