Does divorce occur with repeated self-talk, saying "she is not my wife," while resisting that by saying, "O Allah, I bear witness that she is my wife until the Day of Judgment," and perhaps the husband uttered the divorce, believing it would not take effect with intercourse, knowing that he does not specifically recall uttering the divorce?

All praise is due to Allah, and peace and blessings be upon the Messenger of Allah. As for what follows:

None of what was mentioned results in a divorce. Divorce does not occur merely by self-talk, nor if the utterance is made without intending the meaning of divorce, nor under the influence of obsessions, nor with doubt about its occurrence. The summary is that no divorce has occurred due to what was mentioned; the matter is merely obsessions. Therefore, you must disregard them, pay no attention to them, seek Allah's help, and do not despair. For ways to get rid of obsessions, please refer to fatwas numbered: 52505, 86087, 82731, 31562, 59951. And Allah knows best.