Oaths & Vows

Taking an oath that one will become a kaafir upon doing a certain action

Q: I have heard that if a person takes an oath that “If I do this or do not do this, I will become a Kafir forever”. The person becomes a kafir if he or she swore the oath with the belief that he or she would adopt kufr upon its non-fulfillment. Is this true? I would be very grateful if you could please provide a detailed answer for my satisfaction.

Breaking one's oaths

Q: I have done something that I swore by the Quran, that I would never do again, but I still do it. Then after I did it I swore again that I wouldn't do it, but then I still did it. I know that this time I will never do it again, but I feel like Allah doesn't love me, or trust me, or has forgiven me. And it has been horrible pain. Please someone help me. What is the kaffara for breaking an oath?

Taking an oath to become a disbeliever if one does a certain action

Q: I would like to ask I made an oath that if I do such an such then I am a disbeliever after I marry my fiance who I really want to marry. When I made that oath I felt like I meant it when I said I will be a disbeliever. If I marry my fiance does this mean that I will be a disbeliever? I regret what I said and I am now worried. What should I do, please help me.