Rather than blowing up, which is after you're annoyed, just act calmly and immediately, or don't react at all. When I know I'm on a short fuse because I have cramps and a new letter from the IRS and a filthy house and anything that comes out of my mouth will be shouted, I just don't say anything to my kids until I'm being sane. I let them yowl like banshees and destroy whatever they're wrecking until I make a cup of tea, do a yoga stretch or two, count to ten and realize why I'm pissed. It's really never because of them.
Then when I have my wits about me, I go to calmly give them fair and logical requests, like to stop thwacking their baby sister with the towel rack they dismantled. They can tell by my eye contact, calm voice, and serious tone, that if they do not react, they will only be hurting themselves. I either follow through or not (usually not, because they know I mean business) and we proceed to do things positively together. I make sure to keep a grounded, present watch over the getting dressed and getting out the door, I keep tabs on my temper if they're getting distracted and late, I give easy to understand logical fair directions, and praise while they keep things moving.
Consequences are pretty rare at his point, and my own temper is totally up to me to control. They're great kids, but kids are hard, and I'm tired and have adult baggage, so I don't always feel as Doris Day-ish as I'm acting but it does make me feel better than it would to bully them, and I notice they're happy and having a good time, so that makes up for my own annoyance.
It is very rare that I can't control myself from being a grump, and it's never their fault. When that happens, I just warn them. Like, we were driving to TN once-two days each way, just me and them (3 under 5) and I had SEVERE cramps. The driving day was much longer than I had hoped, and I got up super early to pack and we had a crappy hotel room and no crib (which I had reserved). I had no Motrin, and I COULD NOT SPEAK NICELY. The take out food FINALLY came, we were starving, and there was nowhere to set it down without my one year old grabbing and spilling it, and I couldn't just pop her in a crib so I could eat for 10 minutes. I said, "OK, you guys can jump on the bed and do whatever you want, but I don't feel good and all I can do is yell, so watch out."
I propped up my feet on the suitcase, and anytime anyone bounced over to my bed to block Law and Order I fully yelled at them. Which they thought was super funny and would go screaming to the other bed (usually I make them behave in motels, but all bets were off because I was mad, so I did not discipline them). I just kept a frown and cherished the grouchiness all night since I never do it. They zonked out by 8:30pm FOR ONCE!
Next day, back to normal. It also helps to use humor when you're annoyed. believe me, I am a serious disciplinarian, which prevents a LOT of shinanegans and yelling, and would never suggest humor or yelling INSTEAD of discipline on a regular basis, but if you are usually calm and firm and immediate, it leaves a lot less opportunity for you to get mad and unfair, and humor goes a long way. The kids learn to navigate between "happy funny mom" and "mom who just gave a warning to be heeded". It really is all about self discipline. You KNOW you shouldn't rage at them, so don't. Be fair and logical with your requests, be consistent with your consequences, and don't get mad at them.
Another really helpful thing to do is force yourself to greet them in the morning, first thing with a HUGE happy smile and hug that you're happy to see them. Like every time they wake up in the morning it's the greatest amazing celebration ever. It will make them happy, and force you out of any morning funk you may be in. In our house it's a hard and fast rule.
Even if the hubs and I are in a fight, we stop to give big happy GOOD MORNINGS to the kids from bed, from naps, and sometimes just because someone enters the room. Brighten up. You gotta fake it to make it. Start to greet them with a huge happy smile, then force yourself to compliment them and laugh about something no matter what a few minutes later, and keep your morning on track. If you act happy and loving, you will eventually feel it. Good work seeing this needs to change, you never want to look back like you wasted this time with them. Good luck, hang in there!