Is feeling remorse and recalling past sins—such as combining prayers and yelling at parents—while consistently performing acts of obedience considered a form of waswasah (whispers/obsessive doubts)?

Worrying about sin and self-reproach for it is commendable in Islamic law and is a sign of faith, especially since yelling at one's parents is among the major acts of disobedience (kufr), and combining prayers without an excuse is a dereliction of duty. Regret over sin is the greatest pillar of repentance, but it is not sufficient alone; it must be accompanied by abandoning the sin and resolving not to return to it.