This kind of stuff happens to everyone....It may sound crude but if you think in your head 'Just deal with it and move on...' You will realize that those mistakes are not that bad and you can keep going.
Some of you know that I worked in radio before becoming a cop. One of the things that disc jockeys have to do is get up in front of large audiences on stage. Well, I suffer from stagefright and I would almost go into panic attacks. It took the attitude that this will be over in a moment...I'll go up there, do my thing, and then be done with it. No matter how it made me feel inside, I'd just go and do it.
I took that with me when I left radio...that attitude has come in handy with both police work and when I'm signing. If I'm signing and I make an embarassing mistake (which happens more than I'd like to admit), I take a breath and keep going. One thing I've noticed with police work (especially in training of new recruits) when somebody makes a mistake, it will spiral downhill. They get into their own head and its starts to affect everything after that. In fact, we have a name for it. We call it the 'Jedi Mind F*ck' or 'Jedi Mind Screw'. When you make a mistake, don't let it get into your head and screw the rest of it up. Make Sense?