Is a person held accountable and sinful if he curses Satan, disbelievers, and idols with obscene words when angry due to obsessive whispers, knowing that he is innocent of these whispers and did not intend the meanings implied by them? And what should he do when these whispers come to him?

Satanic whispers do not constitute disbelief (kufr) or sin (ithm), and disliking them is a sign of faith. It is forbidden to curse Satan, disbelievers, or anything worshipped besides Allah, to avoid them cursing Allah in return. It is advised to consult a psychiatrist, occupy oneself with beneficial things, and seek Allah's help while making abundant supplications.