Though Benedict nods, the motion is despairing: it's the knowledge that he has been doing his best, despite everything, and that that isn't, and will never be, good enough.

It wasn't good enough for his mother either, and that bridge is as good as burned now.

Then, "I will help you." His hands slowly lower from his face and he looks at Gabranth, wary and exhausted and imploring. He wants that, even if he can't imagine what could be done differently.