If you can’t put a name on what you feel, it tends to leak out in how you act.

Unnamed feelings do not go anywhere, they come out through behaviour instead: snapping, avoiding, three hours of scrolling, being inexplicably rude to somebody who did nothing. Because the link is invisible to you, it looks like the day going wrong rather than one thing you have not identified. Naming it gives you somewhere to aim, and some of the pressure drops straight away.

Work backwards when you notice the behaviour, and ask what happened earlier. Try a few words until one fits. Say it out loud, even if only to yourself in the car.