“I get perverted thoughts and doubt my salvation!”

Will Christians give an account to God? What is Hebrews 4:13 about? Did Paul disobey God in Acts 18 by going to Asia against His instruction? Is this why Paul was stricken with a difficult circumstance? Might God do the same to us if we disobey? Who is the false prophet in Revelation 2? Could it be Paul? I suffer from scrupulosity (a religious OCD). As a result, I constantly analyze my past performance and doubt my salvation. Can you help me?