Did Nebuchadnezzar ever repent from his evil ways?
Yes. God taught Nebuchadnezzar a painful lesson when his kingdom collapsed. The king realized his sinful ways and acknowledged that the Daniel's God is the "Most High" God. He blessed God, praised and honored Him clearly stating that He forever lives and proceeded to make declarations that Jehovah God has an "everlasting dominion" and His kingdom endures "from generation to generation."
Nebuchadnezzar also said that the God of Daniel does what he wishes "among the inhabitants of the earth." When the Lord interferes in the affairs of men no one can stop Him.
Nebuchadnezzar repents and praises God:
"And at the end of the time I, Nebuchadnezzar, lifted my eyes to heaven, and my understanding returned to me; and I blessed the Most High and praised and honored Him who lives forever:
For His dominion is an everlasting dominion,
And His kingdom is from generation to generation. All the inhabitants of the earth are reputed as nothing;
He does according to His will in the army of heaven
And among the inhabitants of the earth.
No one can restrain His hand
Or say to Him, "What have You done?
At the same time my reason returned to me, and for the glory of my kingdom, my honor and splendor returned to me. My counselors and nobles resorted to me, I was restored to my kingdom, and excellent majesty was added to me. Now I, Nebuchadnezzar, praise and extol and honor the King of heaven, all of whose works are truth, and His ways justice. And those who walk in pride He is able to put down."
At the end of the seven years of living like a wild animal God gave back to Nebuchadnezzar his kingdom. Nebuchadnezzar acknowledged this praising and extolling the Lord calling Him the "King of heaven." He also declared "All his works are truth, and his ways justice." He also gave a warning to those who sought to imitate his failed worldly ways saying God is able to take down all those who strut around puffed up with worldly pride.