What do you do with this pent up feeling when it comes upon you?

I take a nap. I’m old and have learned that acting on emotions (rage) causes more harm than good.

@johnpowell Indeed you have good self control, something perhaps I need to work on. As that does not work for me….

Meh,I just go for a walk…;)

Long fast walk usually does it for me too. That or hitting the wall (literally.)

Attach the pent-up energy to a vacuum, mop, spade or pruners and do some house and garden cleaning.

If you have a strong back, build a dry wall or make a flagstone patio. Reroof, paint a room. Resand and finish floors. Clean car.

That way, you expend the rage and also reap fruits of your labour.

I seriously give thought to what it is like to walk in the shoes of the person that made me feel that way.

I think about how they feel when they wake up in the morning, compared to how I feel (emotionally) when I wake up in the morning, and I usually come to the conclusion that just being them, is punishment enough.

There are people that made me feel this way, because of the things they did to people that I love. And I have thought about revenge and came to this conclusion.

Even if I could make them feel the anguish, fear, pain, horror, anger, rage, that they put my loved one through, that would never erase the fact that my loved one experienced those feelings.

And if I made them pay for what they did, that would take me away from the person I love and that would, ultimately hurt both of us.

Go for anger management counseling.

Since a person has no control over when and where a pent up feeling can happen, I drop my shoulders and immediately control my breathing until it is rhythmical, deeper, and slower out than it is in. When breathing in the diaphram should go down and air should go deep into the lungs. To breathe out just do not breathe in… let the air leak out.
Done no one can hear it and see it you will just look and be more relaxed.