Of course we can control our emotions, we do it all the time! Controlling emotions under pressure is the hard bit.
I just do the exact opposite of how I'm feeling if I'm getting too shirty about something/one. If I feel like ripping someone to shreds (usually well deserved because it takes alot to get me shat off), I smile instead. I still continue what I am doing, so if its a conversation, I stop breathe, smile and keep going. It's usually enough to make the other person mirror what I'm doing and pull the pressure out of the situation.
Just takes practice is all.

