The Briton lies fourth overall, 1:16 adrift of leader Vincenzo Nibali of Italy who took the pink jersey after Saturday's individual time trial.
Team Sky rider Wiggins was expected to claw back the time on his rivals in the individual effort against the clock but finished second to compatriot Alex Dowsett with a display he labelled as "disappointing".
Wiggins, who crashed on Friday and looked vulnerable in the descents in rainy weather, said he had not expected the Giro to be a walk in the park.
"I never expected it to be as straightforward as the Tour last year," Wiggins as quoted as saying in British media on Monday, the race's first rest day.
"Let's be honest, I descended like bit of a girl really after the crash," he said.
"Not to disrespect girls, I have one at home. But that's life and we have to push on and deal with the disappointments."
Most worrying for Wiggins is that Nibali is highly unlikely to just sit back on his lead and wait until the Giro reaches the finish line in Brescia on May 26.
"He will continue to ride aggressively. I can't see him trying to defend 30 seconds from now until Brescia," Wiggins said.
Team Sky, who have been used to defending their lead in stage races, do not have room for conservative tactics anymore and Tuesday's mountainous 10th stage to the Altopiano del Montasio could be a turning point.
"It will be one of the toughest finishes of this Giro, that's for sure," Wiggins explained.
"The race could tip upside down again."
Even though he has been badly shaken since the race started from Naples on May 4, Wiggins believes he is in great form, as he showed in the final part of Saturday's time trial.
"I was physically better than I've ever been," he said.
Wiggins also believes Australian Cadel Evans, the 2011 Tour de France winner who lies second overall - 29 seconds behind Nibali - will have a major part to play in the rest of the race.
"Cadel is the best I've seen him since he won the Tour. He is the danger man in that position. He showed (in Saturday's time trial) he is in good shape."