How can one properly repent, and can this repentance be accepted after molesting a sister, and how can one overcome this feeling of guilt?

However great the sin, Allah accepts the sincere repentance of His servant and forgives him, and repentance erases what preceded it. Indeed, Allah rejoices at the repentance of His servant, loves those who repent, and transforms their evil deeds into good ones, and after repentance, the heart becomes closer to Allah. Therefore, one must strive to achieve repentance, increase good deeds, trust in Allah's forgiveness, and draw near to Him through obedience.