How can one reform oneself and address feelings of hypocrisy, ostentation, and spiritual deadness?

Fear of hypocrisy and showing off is praiseworthy if it leads to striving for sincerity and rectifying intentions. To reform oneself, strive to acquire religious knowledge, act upon what you have learned by observing the obligatory duties and performing supererogatory and recommended acts, abandon prohibitions, avoid causes of evil, associate with righteous people, and turn to Allah through supplication, asking Him to rectify your heart and purify your intention.