Human emotions are highly variable, decidedly unpredictable, and often unreliable. Our emotions are like the weather, only far more fickle. So we must learn to live by faith, not by the ups and downs of our own emotional roller coaster.
Sometime during the day, we’ll probably be gripped by a strong negative emotion. Distrust it. Reign it in. Test it. And turn it over to God. Your emotions will inevitably change; God will not. So trust Him completely as you watch your feelings slowly evaporate into thin air–which, of course, they will.