Is the psychological pain experienced by a person suffering from religious obsessive thoughts (waswas) rewarded, and how can this type of obsessive thought be treated from a religious and worldly perspective?

The source of obsessive thoughts (waswas) is Satan, who is an enemy to humanity. He strives to disturb people and divert them from obedience to Allah, and he casts doubt into their faith and matters of worship. These obsessive thoughts are not harmful; rather, they are a sign of faith, as the Prophet, peace and blessings be upon him, said: "That is pure faith." They are a sign of Satan's cunning, as he finds the believer resisting him, whereas he finds the disbeliever and the wicked person not resisting him.