Cynicism is horrible. It is slowly training your brain to always assume the worst in everything and everyone, and has little to do with expectations. Cynicism legitimizes the anger you already feel, and makes it “okay” to yell about it, rather than taking control of your emotions.
You need a philosophy that allows you to take control, not one that justifies your helplessness. Mindfulness practices, and/or existentialist thought eventually leading to positive nihilism can help you.
Edit: After rereading your initial post, I am doubling down on mindfulness practices. The goal of simply not caring doesn’t seem to be helping you, so perhaps it’s best to try and accept and understand your feelings for what they are, rather than attempt to reject them. Your anger is there, and it is real, but it is your choice to act on it, or let it pass. With time, the practice of “letting it pass” will hopefully result in this being the default position. The brain form habits, and if you start to build a habit of letting go, it’ll get easier.
It’s been Jackbox every year for the past 8+ years. A side-effect of hosting the New Years Eve party for a bunch of gamers.