Amid calls for mass selection changes, Langer said it was the biggest challenge he's seen Australian cricket face.
"When I made my debut in 1993 I came into a team of very senior players. Allan Border was the captain, Mark Taylor, the Waugh brothers - a very senior team. From 89 to now we haven't been in a situation like this.
"Sport is cyclical, there's no doubt about that. Fortunately our cycle went a lot longer than usual," Langer said.
"The reality is, we've seen over the past 12 months or a little bit longer, that our cycle has ... I don't know if we've reached the bottom of it yet, but I haven't seen it [this low] in my career."
Australia held an optional training session at Newlands yesterday, but only a handful of squad members participated. Langer said the low attendance wasn't an issue because some players needed to "freshen up".
The team had an honesty session immediately after the match ended, not even halfway through day three, and vowed to close the book on the debacle as they prepare to square the series in Johannesburg on Thursday night (NZ time).
Langer was confident Australia could turn their fortunes around but admitted a number of issues needed to be addressed.
"I've lost a lot of sleep over it. In the past, really good teams would have thought we're going to do whatever it takes to absolutely bury them. Maybe we got a bit relaxed," he said.
"There's game awareness. You have to adjust. There are times where, if you played the first morning of a Sydney test, Steve Waugh would say to Matthew Hayden and myself, 'I'm going to win the toss and bat here. I know it's going to be hard, but you're going to have to adjust your game.'
"I'm hearing all the cliches come out, flat-track bullies and you can make it when it's easy. We'll cop that on the chin. We have to get better at adjusting to circumstances.
"There's definitely something to that [T20 affecting batting]. It's something we've got to be very aware of.
"You can't ever take away that positive intent but you've got to make better shot selection."
- AAP