I've lost it before - it happens and happens fast. And then we are verbally vomiting all over someone. And afterwards, we feel even worse...not fair!
Here's an Al-Anon saying that I have hanging on my fridge to remind me to button my lip and walk away:
Things can't always go as you want them to. Accept disappointment quietly, cultivate the gift of silence when speaking may aggravate the difficulty.
I am pretty outspoken (aka have a big mouth!) and learning to shut up has been one of the greatest lessons in my recovery. But also the hardest! ; )
You're doing great...hang in there...
~T