How can one overcome feelings of frustration when not receiving praise, and renew the intention to avoid showing off (riya') and hypocrisy (nifaq) in dawah work?

It is permissible to rejoice in people's praise and commendation if the deed was not done for their sake; rather, it might be a part of the believer's immediate good tidings. However, relying on and seeking people's praise is blameworthy. It is advisable to strive for sincerity towards Allah and to know that people's praise avails nothing against Allah, and that the successful one is he whom Allah praises. The stronger a servant's knowledge of his Lord, the more his resolve will turn towards Him. Abstaining from seeking praise is facilitated by your knowledge that Allah alone is He whose praise benefits and beautifies, and whose blame harms and disgraces. This cannot be achieved except through patience and certainty, as Allah Almighty says: "So be patient; indeed, the promise of Allah is true. And let not those who have no certainty disquiet you" (Quran 30:60), and His saying: "And We made from among them leaders guiding by Our command when they were patient and [when] they were certain of Our signs" (Quran 32:24).