One problem that a lot of beginner and intermediate guitar players have is the tendency to want to go back and fix mistakes during a performance.
Now, its ok to correct your mistakes but only during practice time.
It’s VERY important that you also have times when you keep the pace (don’t slow down, don’t repeat notes, don’t go back) and plow right on through your mistakes as if you played them perfectly.
And that can be a difficult thing to do
So if you play 2 bars, and then you have to spend 2 beats getting to the next chord, or the next lick, you can’t get those 2 beats back – they’ve gone.
You either have to make the change on time, or you have to remove those first 2 beats from the lick or chord you were about to play and keep going.
Again, it’s not simple, and it’s not always easy. But it is something you need to spend some time on. When you play you have practice time and “performance” time where you just have to go right on through and keep the time going, no matter what.
When it’s “performance time” you can’t go back in time no matter how bad you want to. Make sure you are making time in your practice time each day to have that performance time so when the pressure is on, you’ll feel comfortable when it truly matters.