StFrancis,
Welcome to Choir Ministry!
I’ve done music ministry of one type or another for over 35 years. My road to sanity is organization:
My current choir uses two main hymnals along with binders for loose-leaf copies of music. I use the same color ribbon or Post-It note for the same part of the Mass, no matter what book the music comes from: white for Entrance, Red for Communion, Blue for Recessional, etc…
My binder has dividers for the parts of the Mass (the Ordinary) and loose-leaf hymns are inserted in the appropriate spots, where they come up in the mass.
All other loose-leaf music, not being used for the current mass, are kept in the back of the binder in alphabetical order.
I do not attend another mass because of distractions at masses at which I minister as cantor, psalmist, or choir-member. I can be just as, or even more distracted sitting with the assembly.
Yes, things should get easier for you as time goes on. You will become more familiar with the music, your choir master’s selections and way of doing things, and you’ll develop your own way of organizing things in your head ahead of time so that you’ll be on the ball when the entrance hymn or antiphon is sung.
Be at peace.