bad mind frame

Today at work I was in a bad frame of mind. I was cynical, and sarcastic, and critical. All just in my mind. Let me give an example: There's a new building going up in our parking lot, and we've gotten so many questions about it. For the longest time, we didn't even know what it was, but customers expected us to. That annoyed me. Now we know, and it still annoys me. Go figure. Today, a woman asked, "do you know what's going on in the parking lot?" I wanted to answer, "there putting up a building," but, of course, that would be sarcastic and rude and inappropriate, so I didn't say anything and let my coworker field the question. I also found myself being very critical of customers, just a bad frame of mind. It's hard for me to get out of when that happens. I still don't have a good way to get out.