Affirmations get a bad reputation for being fluffy - something you say in a mirror and immediately forget. But there's a real reason wearable reminders work differently than a sticky note on your monitor.
A sticky note becomes wallpaper. You stop seeing it within a week. Something you wear moves with you - it catches your eye at a red light, during a hard conversation, in the fifteen seconds before you walk into a room you don't want to walk into.
That's the actual mechanism: not magic, just repetition at the exact moments you need it most, without you having to remember to seek it out.
The words matter less than the habit of noticing them. Pick one that's true enough to believe on a bad day, and let it do its quiet work.