All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
First of all, if the exact words your husband said were: “I give you the divorce,” in the present tense, then it is considered a metaphor of divorce by which divorce does not take effect, except if he actually intended to issue a divorce by saying it. If he did not intend to issue a divorce, then it does not take effect. However, the fact that he told your father that you were divorced may indicate that he intended to issue a divorce. With regard to anger, it does not prevent divorce from taking effect unless the husband was extremely angry, to the extent that he lost his senses on account of his anger (while uttering the words of divorce).
Second, if divorce is issued under coercion, it does not take effect. If what forced your husband to pronounce divorce was his fear that you would carry out your threat to kill him, then the divorce does not take effect, even if he pronounced explicit words of divorce. However, you have committed a serious wrongdoing by putting a knife to your husband’s neck. It is impermissible to terrorize a Muslim. The Messenger of Allah said: “It is not lawful for a Muslim to frighten another Muslim.” (Abu Daawood) If this is the enjoined attitude towards Muslims in general, what about your own husband?
Third, when a husband divorces his wife while she is in a state of ritual purity during which he had sexual intercourse with her, it is a kind of Bid‘ah-based divorce (a divorce that does not conform with the Sunnah). However, according to the preponderant opinion of the jurists, it does take, and that is the view of the majority of the scholars.
Fourth, we advise that your husband orally consults reliable scholars in your country of residence, for there are certain points that need to be clarified by your husband, like his intention, for example, when uttering the words of divorce.
Fifth, a Muslim who is ignorant of the religious ruling on a given issue is required to promptly ask the scholars; Allah, The Almighty, Says (what means): {So ask the people of the message if you do not know.} [Quran 16:43]
Sixth, it is obligatory on you to repent of Zina (fornication/adultery) sincerely and beware of all that may lead to it in the future. Please refer to Fatwa 86527 about the conditions of repentance.
Allah Knows best.