I'm feeling the stress and the weight of expectation for something I am totally unprepared for.
I am not telepathic. I am not God. I'm not that competent a musician. When I'm preparing for any kind of service (even regular Sunday Mass), I need time. I need time to read the readings and pray about them. I need time to go through the Choir's repitoire and select music. If necessary, I need time to choose new pieces, learn them and then teach them to the Choir. The Choir then needs time to learn and get familiar with the music. For things we're not so familiar with, we need at least two rehearsals to get to an appropriate standard.
It seems like this is all extra stuff that I don't have time to get my head around - and work and sleep and live and not go mad. It seems a bit rude to God to have all this stuff coming up and not be able to do (or at least try to do) it well.