Write Now; Rage Later
The trick isn't to suppress it. That will damage you in the long run. The trick is to find a healthy way to release it.
Healthy doesn't necessarily mean "deemed by society to be healthy." Those methods you see on Dr. Oz are things like running a mile or lifting weights or hitting a heavy bag. But sometimes, you just hit whatever's nearest you. Sometimes, you pound the steering wheel while screaming at the top of your lungs. Sometimes, you go to the gun range and put 500 rounds through a large caliber firearm.
Would most people in a rational mood call those things healthy? Maybe. Maybe not.
But some things just aren't healthy. Bar fights. Screaming at people in public (even the ones who deserve it, like smokers who throw butts on the ground or people who yell at their kids). Punching walls and breaking your hand.
And I won't lie. Those things feel good. At the time, anyway.
But the ramifications... Not so much. The trick to finding that healthy way to release the rage really is a trick. You have to trick yourself into going somewhere that isn't right here, right now. You have to make yourself redirect that hostility and anger. You have to leave. You have to go somewhere safe.
It's hard. And the trick I've found that works is to write down, right then and there, what it is you want to do (hit someone in the face, punch the wall, scream, etc). Then head immediately to a safe place, read it again, and unleash holy hell on that steering wheel or heavy bag or what-have-you.
I've had to write a few things down in the past. It's hard. But it helps. I hope it helps you.