WHAT SHOULD BE IN A PERSON'S HEART

It says in Torah 15, "ועקר הדעת הוא בלב" ("The main knowledge of Hashem is in the heart.")

It just occurred to me that here possibly lies the key to conquering our negative emotional states. It takes conscious and dedicated effort to put awareness of Hashem into the place where there used to be despair, emptiness, loneliness, anger, and so on, but the results are really worth it, especially if we merit to persevere in this.