Try and compartmentalising ,it sometimes works for me.
For example when I inform my lino I'm cutting off, everything he says after that I put in the "you really have no people skills and can't cope with pressure" box
When I decide to go over I open the "I'm taking all my break and not listening to the lino whine about the figures" box
Its not right the way some of them go on.
If your down,talk it over with someone,your partner/family/dog...don't bother with the cat though they're selfish
Don't bottle it up
Google the phrase going postal....how many of us are due to boil over?