I try to make the distinction between "warm-up" and "daily maintenance". For me, a warm-up consists of long tones, playing low C for one breath length, then going down chromatically to pedal F or E. I do this two or three times tow get the air moving and lips vibrating freely. Then, I start from low F# and go up as high as I can "gently" and the same for pedal F and E. The whole thing lasts maybe 5 minutes tops. Then I do a daily maintenance routine. My experience is that people call the daily maintenance routine their warm-up.
Now, my range and endurance are always better when I go through that process. But, my teacher has made just start the day by playing Herring Etudes as the "warm-up" because the feeling of being warmed-up will eventually catch up with you and things will work fine. I believe it is part of a larger process to teach me NOT to be so neurotic about either the warm-up or the daily maintenance. Just focus on music and work on technical things within the context of melody. He has said himself that he is no different. When he feels like he is focusing too much on his embouchure and things not working, he takes a step back and pulls out Etudes or repertoire and focus on that.
I think what you are describing happens to us all. Get your mind off how you are feeling and what is not working. Take out some easy to enjoy Etudes or Repertoire, something fun to play and just focus on that until your teacher comes. If there is a friend you can play duets with, all the better.