Is it permissible to show annoyance and weariness from a good deed after performing it with a sincere intention, and does that nullify the reward for the deed?

Finding worship burdensome or mentioning it after performing it does not invalidate the reward if it was done sincerely for Allah. The perfect believer performs worship with pleasure and joy, and through striving and perseverance, the hardship of worship transforms into delight. Thus, one no longer finds it burdensome but rather yearns to perform it again after its completion.