Iggeret HaTeshuvah Chapter 7: Part Three http://www.chabad.org/library/tanya/tanya_cdo/aid/7940/jewish/Chapter-7.htm
TANYA: CHAPTER 26 Part Six "Coping with Failure II" Successful strategies for overcoming depression despite personal failings.
TANYA Iggeret HaTeshuvah Chapter 10 - Part Two On a Wing and a Prayer ~ Experiencing Tefillah’s Uplifting Energy Properly