Thiago Silva was badly missed by Luiz Felipe Scolari's men, who were torn apart and conceded five times in the opening 29 minutes in the semi-final loss.
As his side prepare to face the Netherlands in the third-place play-off on Saturday, the Paris Saint-Germain defender said he had struggled to sleep since the Germany loss.
He said the defeat would only make Brazil stronger.
"The frustration is immense. I spent some nights with insomnia, thinking about this World Cup, on this possible final match and this won't happen anymore," Thiago Silva told a news conference.
"But, I always had motivation to play football. I think when we love what we do, and it doesn't matter the situation we have to learn with our mistakes.
"Our errors during the last game will make us stronger."
