I've been in situations like yours a few times too. Afer about the fifth one (pretty quick, I know), I become desensitized to it. Its like that Dilbert cartoon, that goes something like - "Your performance in this project has been... simian." "Woohoo!"
I find its a far more efficient use of my time, nerves, and energy to select another target to pursue rather than overanalyzing what went wrong (not saying you shouldn't analyze at all - but not quite that much
).