What was the story with S'dom? Rebbi Moshe Shapira z"l explains that they took the concept of midas hadin (attribute of judgement and exact measure) to the max, and held that each person should only live specifically according to the "letter of the law" and his own personal abilities. Thus, they forbade any form of chesed, tzedaka, and acts of kindness and mercy, for these are all concepts of "beyond the letter of the law" and of giving to others what they do not have themselves. Hashem saw this, and responded as follows: "I see that you like midas hadin. Ok, I will actually 'help you' with this and bring it out in its fullest." This was the Divine Fire that Hashem sent on S'dom. Fire represents midas hadin at its fullest, for fire is unique in that it destroys and breaks apart whatever it comes upon. (This is all the exact opposite of the Dor haMabul, the Generation of the Flood, for then the sin was in midas hachesed, the kindness attribute, used improperly, where there were "giving" and procreating in forbidden manners, so Hashem there too responded measure-for-measure with Water, which represents giving and unity).
Every person is made up of the four basic elements, fire, water, dirt, and wind, each representative of different characteristics, some more with one, and some more with another. There is Mr. Water, Mr. Dirt, Mr. Wind, and Mr. Fire. Now the smart person "meditates" on his own self and tries to bring out whatever his quality is (each of us is a combination) in a positive manner (with the guidance of his private rebbi).
With regard to innate drives and techunos (like we're discussing here), one should go with them, in a positive matter. But for breaking bad middos (like depression, anxiety, negativity, feeling like a zero, etc.) one should go to the opposite extreme (with a rebbi), like the Rambam says (Deios 2:2), as well the Vilna Gaon (Even Sheleima 1), and the Madreigas haAdam (Birur haMidos 3).
