After a tough run of results, City looked to be heading for victory in the Manchester derby when Josko Gvardiol planted a 30th minute header from Kevin De Bruyne’s cross.
But United punished late mistakes with Bruno Fernandes scoring from the penalty spot and Amad Diallo scoring a 90th minute winner.
Guardiola has urged his players to remain calm and says they have set high standards that they are struggling to meet.
“Football, like all of life, is emotion and how you feel,” the City boss said. “Now we are more anxious with the ball and without the ball.
“The worst thing as a defender and striker in the boxes is when you are anxious. You have to have this composure and calm that nothing wrong is going to happen and you are calm when making decisions.
“Momentum and confidence and our standards are high. Myself and the players do it. All the things we have done is because we have solved it.
“I said many times to relax. If you are in the box, always you have tempo and time, now we are not doing that.”
Watch Pep’s press conference in the video above…