Try ignoring your coach's advice for a few nights and play that stuff the way you know it was meant to be played. Just see what happens - might be good, bad - either way you'll learn something valuable and you can work with that for the next gig.
From my perspective, there is nothing less interesting than a live band doing a cover so effectively that you wonder if it's just lipsynch'd. What's the purpose of that?
I remember some years ago I saw a friend playing in a bar at my home town. He looked good, trim, sober, clean and all that. I was psyched to hear him once more after all these years. Back in the '70s when I was in high school, this guy fronted one of the area's hottest rock'n roll bands and had done so for years - he and the band were local legends. They could do covers really well and had their own material - and used real Leslie cabs - real B3s - light show, the works. So he was kind of a hero to me.
When I saw him at his solo gig more recently, I couldn't take it and finally had to leave. Here was this guy who could match talent and chops with anyone on any stage in the country - playing his original '50s Les Paul and singing through his SM58 - to his own prerecorded tracks of a full band. I could tell he'd done it all as it was not a karaoke thing. But there was just him and his little box of lights - under some blue light in the corner of this dark bar doing Al Stewart and Air Supply covers on a Saturday night for six people who were watching a football rerun on a corner TV. It was like watching someone who was dying just a little bit at a time over thirty years.
Man, I wanted to cry right then and there.
Make the music your own - Put your life and your love and your anger into it. If you lose the bar gig, find another bar. But don't let routine kill the joy of this for you. This may or may not be your life - but I'll wager it's a big piece of your soul.
Fall seven times; stand up eight