What is the ruling on an oath of divorce in my situation: "I swore to my wife by divorce that she would not go to her sister's house, and she did not go. I then swore to her a second time by divorce that if she went to her, she would be divorced, and by my oath, I truly intend divorce if she goes." So, if I come to my senses and allow her to go, does it count as one divorce, two divorces, or does the divorce not occur at all?

If by your oath you intended to effect a divorce upon your wife should she go to her sister's house, then upon her going, the divorce occurs. As for repeating the oath concerning the same matter, unless you intended thereby to reiterate the divorce, it does not necessitate multiple divorces; rather, a single divorce takes place. It is stated in the Hashiyat Tuhfat al-Muhtaj: "And if he repeated concerning a consummated or non-consummated marriage, 'If you enter the house, you are divorced,' it does not multiply [the divorce] unless he intended a new declaration, even if there was a long interval or multiple sittings."