After the declarations of the Lord against Assyria and their king, Sennacherib still stood ready to attack Judah and their king Hezekiah. During the night, however, the Angel of the Lord went out and killed 185,000 Assyrian soldiers, and their fellow warriors found their corpses the next morning. At this sign, Sennacherib went home to Nineveh in Assyria. While he was in the temple of his god, Nisroch, two of his sons killed him with swords and ran away into Ararat. His son Esarhaddon then reigned in his place.
Be comforted in the fact that once God speaks something, He will perform it. God told Hezekiah through Isaiah that they would be blessed and protected, and that the king of Assyria would be stopped, and that is what happened. The Angel of the Lord, presumed by most scholars to be a pre-incarnate appearance of Jesus in the Old Testament, went into the camp of the Assyrians and killed a major portion of their army. When Sennacherib went home, he was killed as well, by members of his own family. The defeat was complete. God does not do things halfway. He does not leave you stranded. There may be times when you will not understand His ways or doings, but God will always do what He promised to do. Stand on that fact, live in that promise. God is faithful! One additional note: while in Ninevah, Sennacherib was killed. The judgement of God came upon him forcefully. Yet, God would send Jonah to this city to offer mercy and grace to them at another time. Is that not just like God. He does not execute judgement without the companion offer of grace.