Waswasas of Kufr

Q: I suffer from a lot of waswas about kufr. So sometimes I utter the Shahada to calm my mind. Does this affect my Nikah? If I hadn't actually comitted kufr but uttered the Shahada out of fear I had comitted kufr, would I consequently have to renew my Nikah as well? Sorry if you find the question strange, but these kind of things are in my head.