"Now everything is more difficult in our mindset, but we'll be there. We'll try with our people at the end, we agree we can do better to be most active in the final third and we'll try," the Spaniard told reporters.
Guardiola, who has faced Real Madrid 29 times in his career winning 14 matches, could at least take some comfort from avoiding an even heavier defeat when Gianluigi Donnarumma saved a penalty with little more than 30 minutes remaining.
"I didn't feel powerless," Guardiola added, showing characteristic resolve despite his team's struggles.
On the other side, Real Madrid coach Alvaro Arbeloa was celebrating a performance that provided welcome relief in what has been a rollercoaster season.
The two-time Champions League winner as a player has enjoyed a promising run since taking over from Xabi Alonso in January, but has also endured spectacular falls against minnows Osasuna and Getafe.
Uruguay's Federico Valverde proved the hero of the night, scoring as many goals in the first half as he had managed in his previous 75 Champions League appearances combined.
"I don't know if in the end he's going to end up hating me because of how annoyingly I've been nagging him about trying to convey how important he is to the team," Arbeloa said.