Stoicism is not about repressing emotions — it’s about not allowing emotion to override reason. But emotions such as anger and fear most easily override reason.
From Meditations by Marcus Aurelius
Why feel anger at the world? It’s not like the world would notice (7.38).
When you lose your temper, or even feel irritated, remember that human life is very short. Before long all of us will be laid out side by side. Remember how much more damage anger and grief do than the things that cause them (11.18).
And expecting bad people not to injure others is to ask the impossible. Further, to let them treat other people like that but expect them to exempt you is arrogant — the act of a tyrant (11.18).
It’s all in how you perceive it. You’re in control. You can dispense with your judgments at will (12.22, see also 8.47).
It’s silly to try to escape other people’s faults. They are inescapable. Just try to escape your own (7:71).
Personal reflection: Easier said than done. Marcus is right. But anger is powerful.