Have you read Isaiah 38 and Isaiah 40:29

Hezekiah’s illness 1At about that time Hezekiah became deathly sick. The prophet Isaiah, Amoz’s son, came to him and said: “The LORD God says this: Put your affairs in order because you are about to die. You won’t survive this.” 2Hezekiah turned his face to the wall and prayed to the LORD: 3“Please, LORD, remember how I’ve walked before you in truth and sincerity. I’ve done what you consider to be good.” Then Hezekiah cried and cried. 4Then the LORD’s word came to Isaiah: 5“Go and say to Hezekiah: The LORD, the God of your ancestor David, says this: I have heard your prayer and have seen your tears. I will add fifteen years to your life. 6I will rescue you and this city from the power of the Assyrian king. I will defend this city. 7This will be your sign from the LORD that he will do what he promised: 8once the shadow cast by the sun descends on the steps of Ahaz, I will make it back up ten steps.” And the sun went back ten of the steps that it had already descended. 9A composition by Judah’s King Hezekiah when he was sick and then recovered from his sickness: 10I thought, I must depart in the prime of my life; I have been relegated to the gates of the underworld for the rest of my life. 11I thought, I won’t see the LORD. The LORD is in the land of the living. I won’t look upon humans again or be with the inhabitants of the world. 12My lifetime is plucked up and taken from me like a shepherd’s tent. My life is shriveled like woven cloth; God cuts me off from the loom. Between daybreak and nightfall you carry out your verdict against me. 13I cried out until morning: “Like a lion God crushes all my bones. Between daybreak and nightfall you carry out your verdict against me. 14Like a swallow I chirp; I moan like a dove. My eyes have grown weary looking to heaven. Lord, I’m overwhelmed; support me!” 15What can I say? God has spoken to me; he himself has acted. I will wander my whole life with a bitter spirit. 16The LORD Most High is the one who gives life to every heart, who gives life to the spirit! 17Look, he indeed exchanged my bitterness for wholeness. You yourself have spared my whole being from the pit of destruction, because you have cast all my sins behind your back. 18The underworld can’t thank you, nor can death praise you; those who go down to the pit can’t hope for your faithfulness. 19The living, the living can thank you, as I do today. Parents will tell children about your faithfulness. 20The LORD has truly saved me, and we will make music at the LORD’s house all the days of our lives. 21Then Isaiah said, “Prepare a salve made from figs, put it on the swelling, and he’ll get better.” 22Hezekiah said to Isaiah, “What’s the sign that I’ll be able to go up to the LORD’s temple?” He gives strength to the weary and increases the power of the weak. https://temtube.com/