Expelling fear and why we experience it:
The Baal Shem Tov stated: One who is overcome by sudden external fear is receiving from the right hand of Hashem. Hashem sends him this fear in order so he come to an inner fear of Hashem. Furthermore, when one recognizes that the fear he is experiencing is in truth an act of kindness from Hashem, then this fear can turn into love, and this love expels the external fear. [This statement is referring to external fear of worldly matters. The intent of this statement is to say that one who is struck by fear and paranoia it is in order for him to come to a true fear of G-d, and eventual love of Hashem, and the way to expel these fears is through revealing the love.] This however only works if one’s intent is to truly serve G-d with love and fear. If however his intent is simply to rid himself of the fears, then it will not help at all.
 Ben Porat Yosef Toldos 49/4; 50/1; Keser Shem Tov 38-39