Focus on your game, not your results during short periods. If you make better decisions than your opponents, you'll be a long-term winner, but that doesn't mean you'll win consistently. Control what you can, your play, and don't concern yourself with the unavoidable ups and downs due to variance.
That said, be critical of your play. When you stop playing as well as usual, you want to recognize it asap instead of automatically assuming the cause is variance.