Gregory the Dialogist

For the thing that I greatly feared is come upon me, and that which I am afraid of is come unto me. The righteous therefore lament and fear, and torment themselves with bitter lamentations, because they dread to be given over, and though they rejoice in their own correction, the correction itself disturbs their fearful spirits, lest the evil, which they are undergoing should not be the merciful stroke of discipline, but the righteous visitation of vengeance. …

Morals on the Book of Job, Book V ↗

Thomas Aquinas

Because bitterness of soul arises from unhappiness, after he speaks of the bitterness of his soul, he next speaks about his unhappiness saying, "For the thing that I fear comes upon me." Note here that the unhappiness of man which provokes bitterness seems to consist in two things. First, in the damage to his things or his person and in dishonor. As to the first two, he says, "For the thing that I fear comes upon me," i.e. those things which I fear happen to me. …

Commentary on Job ↗