Chris Powell admitted his side lacked mental strength after they crashed to a humiliating 2-1 defeat at Dagenham.
Jon Nurse put the Daggers in front with a powerful finish and Danny Green doubled their advantage with a shot into the top corner.
The faltering Addicks grabbed an injury-time consolation effort through Frank Nouble.
Yet Powell, whose men came under fire from the visiting supporters, conceded: "When you're in a period of low confidence then things will eat away at the players.
"Confidence is a fragile thing and it's more mental now, not physical.
"We're maybe a little bit afraid to try things and naturally thinking it`s not going to be our day. That's a mental issue and that's tough."