You can lose a game without losing your temper. Those are two separate scoreboards.

The result and your conduct are tracked separately, even though it rarely feels that way in the moment. One is decided by the other team, the referee, luck and whatever your legs had left. The other is entirely yours, and it is the one people remember a season later. Losing badly is not the same as losing well.

Decide now what you will do in the ten seconds after the final whistle of a bad loss. Shake hands, say one sentence, keep walking. Having picked it in advance is what makes it possible when you are furious.