I need scriptural evidence to show why God may reveal how we die or the period and what to do when having such visions?
God revealed to Hezekiah that he was going to die, but Hezekiah prayed and God gave the man 15 more years:
"In those days was Hezekiah sick unto death. And the prophet Isaiah the son of Amoz came to him, and said unto him, Thus saith the LORD, Set thine house in order; for thou shalt die, and not live.
Then he turned his face to the wall, and prayed unto the LORD, saying,
I beseech thee, O LORD, remember now how I have walked before thee in truth and with a perfect heart, and have done that which is good in thy sight. And Hezekiah wept sore.
Turn again, and tell Hezekiah the captain of my people, Thus saith the LORD, the God of David thy father, I have heard thy prayer, I have seen thy tears: behold, I will heal thee: on the third day thou shalt go up unto the house of the LORD.
And I will add unto thy days fifteen years; and I will deliver thee and this city out of the hand of the king of Assyria; and I will defend this city for mine own sake, and for my servant David's sake." II Kings 20:1-6
The revelation to Hezekiah had a purpose for you and for me. It lets us know that God is in control and that He is paying attention to those who are talking to Him.
Are there other purposes for Hezekiah or for you or for me?
One thing we discover, if we continue reading, is that Hezekiah, one of the better kings, made what was perhaps his worst recorded mistake when he showed everything in his house and in the Lord's house to visitors from Babylon. The Babylonians would later conquer Judah and carry away the treasures of his house and of the Lord's house.
Perhaps it would have been better if Hezekiah had simply left things alone when he was told that he was going to die. Perhaps he should not have prayed for an extension to his natural life.