"Personally I feel that I can either communicate with an audience or with a songsheet and I have chosen the former. This may lead to occasional lurches in the lyrics but so be it. Mike and I spend a lot of time becoming familiar with a song (sometimes months) before we give it its first outing."

1st point - After over 20 years in teaching I find it amusing anyone might consider the human brain not being able to cope with communicating with an audience and a songsheet/cribsheet/prep-sheet at the same time. Lurches are a challenge, and learning how to handle them can be a rewarding experience and valuable skill when learned.

2nd point - "Months" of working on a song is a habit you may find difficult to break. A slow-release chill patch on your upper arm might help here. Take a long-term break from monotony.

3rd point - I specialise in "off-the-cuff" & "hot off the press" songs (performed for the 1st time in public, without ANY practice at home) and it's an exhilarating experience. It's called risk-taking. It's what puts us at the head of the animal kingdom. Use your brain more and worry less about perfection and you might be surprised how much faster you progress.

Good luck with it.