If at all possible it is important to briefly remove yourself from the situation (even if for a few minutes)(even if done in the privacy of the restroom.) During the self compassion break it is necessary to put the "story " of what happened on hold. Then you will soothe your upset state by validating your emotions.
Then, acknowledge to yourself that "this is really hard right now." Hear and validate yourself first. Accept and care for yourself first. This will help de-escalate your emotional reactivity to the situation and put yourself into a more peaceful state of mind.
I have found this to be quite helpful and validating of my own feelings and experiences. I find that with practice comes a great deal of self soothing and I automatically switch into this way of thinking when I am upset. See what you think.
1) put 1 or 2 hands over your heart or another place on your body that is soothing.(by doing this we remember to be kind to ourselves)
You might say to yourself "this is a moment of suffering." (Here we acknowledge mindfully that we are suffering.)
2) Say to yourself- "suffering is a part of life" (Here we acknowledge our common humanity.)
3) Affirm: May I be kind to myself. (Here we acknowledge the additude of self compassion)
"Self Compassion: stop beating yourself up and leave insecurity behind" by Kristin Neff, PH.D ;2011
Other resources on Self Care/Self Compassion:
Trauma Stewardship- An everyday guide to caring for self while caring for others-
by Laura Van Dernoot Lipsky
The Giving Tree- Shel Silverstein
Self care for Caregivers- Pat Samples