Let the Frustration Out

I have a tendancy to let my anger and frustration build up over time. It is like I am afraid to let it out, and I fear that once I start, I will not be able to stop. It is like I think that if I uncork my bottle full of emotion, I will not ever be able to put the cork back on if I needed too.
So, I do not tell people how I feel, other then my therapist, and I let my anger build. This leads to a huge explosion. It starts with a rough morning, of forgetting to bring something to school, or missing the bus. Then, I have a terrible day at school, getting laughed at by my classmates. I take the bus home, getting more crap from classmates, and then I run into my parents. My father is inevitably in a terrible mood and yells at me, causing me to go off, not on him, but on my mom. I take a lot out on her. I do not do it on purpose, but it is like, I yell at her because I know that she will still love me, even after I through a fit or flip my lid.
This pattern of holding it in and then blowing up is not working for me, my family, friends, or my mental health. I have never really looked for a release for stress or anger before, and I fill a bit silly doing things to let out anger. Punching a pillow does not work for me, but I yelled into a pillow for 2 minutes the other day, and felt surprisingly better. But, I can not just go around, soaking pillows with spit as I yell into them.
Stressballs are fun, but a chunk of sculpy clay is more effective in letting me let out my anger. And Animal Crackers. Biting someone's head off, after naming it, is nice, but I do not want to be relying on food for anything, even if it is not a daily thing.
I have not really tried anything else to relieve stress, I do not know much of how, so any suggestions would be greatly appreciated. Like, something to do instaed of yelling into pillows, scribbling and smashing balls of clay, making loud grunting noises. I am all ears.

The Girl Uninspired.