Is supplicating for those whose state of belief – whether they are disbelievers or not – is unknown considered an act of disbelief? And does Allah forgive repeated repentance from disbelief?

The questioner is advised to disregard the numerous obsessive thoughts he is experiencing. The questioner has not fallen into disbelief. Whoever intentionally commits a sin should hasten to repent, for Allah accepts the repentance of those who repent and rejoices in it. Allah Almighty says: "And whoever does evil or wrongs himself then seeks forgiveness of Allah will find Allah Forgiving and Merciful," and He Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'"