What is the ruling on doubting the number of Rak'ahs (units of prayer) when one is unable to base their action on the minimum, and what is the ruling on doubting whether one has performed the prayer, and how can one get rid of obsessive thoughts (Waswas)?

Whatever doubt you experience regarding your prayer, do not pay attention to it unless you become absolutely certain that you have abandoned it. This is because if doubt in prayer becomes frequent and turns into obsessive whispering (waswās), it is of no consequence. The person afflicted by waswās should not pay attention to these whisperings but rather disregard them. We advise you to adhere to supplication (du'ā') and earnest plea, and to distract yourself from these whisperings. You may also consult a trusted psychiatrist.