Don't sweat it...I get canker sores related to stress. While not outwardly visible they do impact on my speech if they are bad enough.

As I've gotten more experienced at the practice I have learned how to manage the stress better and how to avoid the stress in some cases. You'll learn how to manage your stress better and the rest of it is out of your control.

Little comfort I know, but if people (clients or lawyers) have a problem with cold sores then you probably don't want to work with them.

IL