How can one clear their conscience and clarify the reason for not speaking on a certain matter, especially after having sworn on the Qur’an not to divulge it, while it has been spread by others?

It is impermissible for someone entrusted with a secret to reveal it. If he reveals it, he is betraying the trust, based on the Prophet's (peace and blessings be upon him) saying: "If a man narrates a hadith and then looks around, it is a trust," and Allah's Almighty saying: "O you who have believed, do not betray Allah and the Messenger or betray your trusts while you know [the consequence]." However, if the secret spreads from someone other than the one entrusted with it, then there is no blame on him for disclosing it, nor is expiation required of him. He should clarify that the matter was a secret entrusted to him.