Is my supplication against my friend—after I revealed his secret and he insisted on denying my claim—and the fact that the supplication has been answered by him not having children until now, an indication that I have been wronged? And is my supplication considered unjust?

Disclosing a secret is a betrayal of trust and forbidden if it causes harm to a friend, because it is injustice and treachery. The texts have indicated the prohibition of disclosing a secret, especially if it is harmful, as it is betrayal and baseness. As for a man revealing another's secret, it is uglier than revealing his own secret. Nevertheless, there are cases where disclosing a secret is permissible or obligatory if there is a legitimate and recognized need. However, if there is no legitimate need, disclosing a secret is considered an aggression and a betrayal. If your friend calls you a liar, the sin is upon him. As for supplicating against him, it is permissible if his calling you a liar resulted in injustice. However, if he did not wrong you, it is not permissible, because supplicating unjustly is considered a sin.