Via the comments, from the always on-point Sarah Rooftops:
I agree the rest of the world doesn’t need to cut you slack, but if I’m having a *really* tough time of it I’ll tell my colleagues, “I’m stressed right now - I’m trying not to be snippy with you, but if I am, I don’t mean it.” But no, they absolutely don’t need to know the details!
She is quite right. It’s not that stress doesn’t have a real, and valid, impact on your behavior, even though you should do your best to minimize it to the world at large. But there’s a big difference between saying, “You know, I have a lot on my plate right now and I’m not at my best — please accept my apology, it’ll all be over by Tuesday.” versus “WHAT DO YOU WANT? I am so stressed! I cannot DEAL with it! UGHHHH!” and then launching into the List of Things That Are Stressing You.
You can and should state facts: “I have a lot going on right now and I can’t tackle anything else at this minute.” But you can’t use it as an excuse to be bad to people.