What should a divorced woman do who committed adultery with a married man while she was in her waiting period (iddah), and how can she repent from this sin without causing problems with the man?

The abominable sins you have fallen into are destructive. Therefore, hasten to sincere repentance by regretting them, abandoning them, and resolving never to return to them, while adhering to acts of obedience. Allah the Almighty says: "And those who do not invoke with Allah another deity or kill the soul which Allah has forbidden [to be killed], except by right, and do not commit unlawful sexual intercourse. And whoever does that will meet a penalty. Multiplied for him will be the punishment on the Day of Resurrection, and he will abide therein humiliated – Except for those who repent, believe and do righteous deeds; for them Allah will change their evil deeds into good ones. And ever is Allah Forgiving and Merciful." Repent and conceal yourself, cut off your connection with that man and all means of communication with him, and change your place of residence, phone number, and work, if possible, to avoid meeting him.