The important thing is knowing how to reach out for help if you ever do need it. Making a plan in advance about what to look out for when emotional releases occur during a massage session, what to do if you ever find yourself in a situation that you think is more than just a normal emotional release, and knowing what resources are available for help for you or for your client, can be some of the most important things you may ever do in your practice.
You may never need them--most people won't ever face this situation. But if you ever do, then having made a plan in advance, and knowing who is in your community who can be of help--both to your client and to you--can lead directly to your saving a life. And saving a life, when you consider all the future events that will cascade from that person's effects on others, is as if you saved the world.
It's just that important.