I would say that I have an anger problem, but I've been getting better all the time. I turn 19 on monday... I punched a hole in my door before I moved out (moved out in august) that I still need to pay my dad for... It was unavoidable (for me) with all the stuff piling up. I got a ticket on top of having a horrible time with everything and all this shitty stuff stacked up until I hit something... I either stubbed my toe or hit my head or something on this
REALLY hard wood and I just went "
FUUUCK!!" and punched the door and my fist went 3/4 of the way through it. Whoops! That was embarassing.
Before that, a bunch of shitty awful stuff stacked up and my nephew was actually the catastrophic trigger. He didn't know how pissed I was and he like... tripped me or pushed me and I stumbled over my feet into something and hurt myself and tried to walk away to cool down but I got near this tall lamp and I punched it. The light bulb exploded instantly before anything could even fall over. That was with my dad sleeping in the same room. Ah, how embarassing.
Since then I've become more of a pothead, which rather than necessarily just helping by like calming me down or mellowing me out, it allowed me to see things from different perspectives (along with other drugs I'll admit

) and just thinking about stuff like that I'd go, "What's the
point in wasting so much energy on getting angry like that?"
Basically, what worked for me was like psychedelics and introspective thinking. Hahaha. Not for everyone, but just like... sit back and
think. Just think about how fucking ridiculous it is to get so mad over some stupid petty shit that you'll forget about in a month. Hope you find something that helps...
EDIT: Oh, and figuring out yourself helps. I'm relatively passive-agressive, always have been, but I've been working on it and as I've been preventing myself from bottling everything up inside 'til I explode (just stopped caring, tell people what I think, yadda yadda) it doesn't build up to the breaking point like it used to.