Intense urges and how to resist them

I've had a rough patch recently and can't really place why. I'm a natural cynic and pessimist and sometimes I get incredibly frustrated that there are so many things that happen that make my life hard and I can't do anything about them. I feel helpless, and sometimes a small thing can happen that sets me off and I end up feeling angry.

I get an intense tightness in my chest, an agitation that I struggle to resist and a severe urge to hit something to SH or to SH in some other way. I've seen various pieces of advice to help resist urges, which sometimes work if I get tipped over in a sad way rather than an angry way, since it seems to be one of the two. In those cases distractions often work, because it's a lower-energy reaction and my brain is wandering slow-time. But when it's an angry urge, my brain kicks into overdrive and I can't focus on anything other than the thing that tipped me over which only winds me up more, and I have to do something about it.

Problem is this often happens at work where I have very limited options. I often can't leave the room I work in, so separating myself is out of the question. I can't draw on my arms or have a hairband around my wrist due to uniform policy, I can't distract myself because I have a job to do, I can't exercise because I can't leave work, or go for a walk, or something like that. No access to ice cubes to hold, no taps to run hands under sometimes, no ability to listen to music, anything like that. Essentially I need a solution that I can enact without leaving the room or being 'distracted' for more than a couple of minutes.

If anyone has any ideas what I could use for this, I would be grateful. I've heard breathing exercises are supposed to be good but often I can't switch my brain off still amongst them and end up leaning more to hyperventilation than relaxed breathing because I'm trying so hard to chill out.