Iggeret HaTeshuvah Chapter 7: Part Three http://www.chabad.org/library/tanya/tanya_cdo/aid/7940/jewish/Chapter-7.htm
TANYA CHAPTER 27 Part One "A Frum Frown" Why meticulous observance might induce depression, and how you can to turn it into joy!
TANYA CHAPTER 27: Part Six "Liberating Restraint" Harnessing the power of restraint uniquely catalyzes divine satisfaction.