It is one thing to be a terrified sinner and another to be a repenting sinner.
Thomas Watson, The Doctrine of Repentance, 1668
Here is the context of that quote.
Do not be deceived! This is not true repentance! Both Ahab and Judas had great trouble of mind. It is one thing to be a terrified sinner—and another to be a repenting sinner. Sense of guilt is enough to breed terror in the conscience. Only infusion of divine grace, breeds true repentance. If pain and trouble were sufficient to repentance, then the damned in hell should be most penitent, for they are most in anguish. “Men gnawed their tongues in agony and cursed the God of heaven because of their pains and their sores, but they refused to repent of what they had done!” Revelation 16:10-11. Repentance depends upon a change of heart. There may be terror—yet with no change of heart. “I preached that they should repent and turn to God and prove their repentance by their deeds.” Acts 26:20
Thomas Watson, The Doctrine of Repentance 1668