Allow others to be where they are. Focus instead on your own state of being.
"Do not let the behavior of others destroy your inner peace." — Dalai Lama
The only person who can give inner peace to you is YOU.
No one else can give inner peace to you. Your spouse cannot give it to you. Your children cannot give it to you. So make your own inner peace your top priority.
If your kids are acting up and you're feeling stressed or frustrated, tell them that you're taking a time-out and will come back once you've calmed down. Likewise, if an angry person upsets you, walk away instead of immediately firing a response at them.
Keep your own sanity. Don't allow another person's anger or temper tantrum to infect you and spoil your day. Nothing is worth sacrificing your sense of well-being.
The next time something interferes with your inner peace, just walk away. Then find a quiet place for yourself and breathe slowly and deeply to calm yourself down. Bring yourself back to center as you imagine what just happened as melting into a heap of dust that then gets washed away. Once you feel peaceful again, ask what you needed to learn from that experience. Last, if necessary, try to re-engage with the upset person from a centered place and see if you get a better outcome.
Peace of mind comes from not wanting to change others. That means honoring how others express themselves and to stand firm in your own inner peace.
I think of it this way: when I'm lying on my death bed, the small stuff won't matter to me anymore. Even big stuff might not matter as much. The only thing that will matter is how I lived and loved.