It's easy to get overwhelmed from time to time when you're parenting children. It happens to the best of us. There are a few things you can do to help calm yourself down in the heat of the moment.
You can slowly count to 10 and breathe deeply. In through your nose and out through your mouth.
Try to change the scenery. It may not be easy to leave the house or go for a walk, but you can take your children elsewhere and let them play outside and get a breath of fresh air to get away from where the stressful event is occurring.
Try to reframe the situation and see it from another point of view. You can always play some music—it can be soothing, calming, or fun and silly music you can get up and dance around the house to with your kids. Anything to try to change the temperament and the mood.
Always try to control your anger before it controls you. Our kids are always watching and learning from us. It's not a matter of if you'll get mad, but when. So model good behavior, and teach your kids what to do when they get mad, too.