Are recurring thoughts about swearing by divorce during buying and selling, and doubting the occurrence of divorce in the event of perjury due to phrases such as "I will not sell it for such and such" or "I will not buy it for such and such," mere whisperings (waswas)? And is the only solution to ignore them and not succumb to them?

Oaths of divorce are not binding merely by self-talk without uttering them, and doubt about utterance is not to be heeded. And assuming utterance due to the overwhelming power of whispers (waswas), no divorce occurs and nothing is binding. All of this is merely whispers that have no consequence, and one must turn away from them. Among the greatest aids in getting rid of them is seeking help from Allah and frequently supplicating.