Your premise that only God can have that name is incorrect therefore the conclusion you arrived at based on this false premise is equally incorrect.
See, for example, Exodus 23:20,21. The name was conferred on the Angel. Was that Angel therefore God?
It is interesting that the Father GAVE the name to Jesus. It was conferred upon him just as it was upon the Angel. That Angel was called the "Angel of God's presence." The Angel held that name until the resurrection of our Lord and then it was then conferred upon Jesus. [see Isaiah 63:9; Hebrews 1 - the whole chapter but especially verse 4]. In Hebrews 1, there is no doubt that Jesus receives everything from his Father. How then is Jesus equal to the Father?
How is it that the glorified Christ is still called a man if he is indeed God?
1 Timothy 2:5For there is one God, and one mediator between God and men, the man Christ Jesus
If the Father and the son are equal, how can Christ turn the completed work of the restoration of the earth over to his Father at the end of the Millennium?
1 Corinthians 15:28 And when all things shall be subdued unto him [i.e. Christ], then shall the son also himself be subject unto him that put all things under him, that God may be all in all.
If Christ is subject to God, having relinquished, at the end of the Millennium, the "all power in heaven and in earth" authority granted to him by the Father, how are they in any sense equal? Examine the "type" or foreshadowing of this role so wonderfully provided in the story of the relationship between Joseph and Pharaoh:
Genesis 41:39-44 And Pharaoh said unto Joseph, Forasmuch as God hath shewed thee all this, there is none so discreet and wise as thou art: 40 Thou shalt be over my house, and according unto thy word shall all my people be ruled: only in the throne will I be greater than thou. 41 And Pharaoh said unto Joseph, See, I have set thee over all the land of Egypt. 42 And Pharaoh took off his ring from his hand, and put it upon Joseph’s hand, and arrayed him in vestures of fine linen, and put a gold chain about his neck; 43 And he made him to ride in the second chariot which he had; and they cried before him, Bow the knee: and he made him ruler over all the land of Egypt. 44 And Pharaoh said unto Joseph, I am Pharaoh, and without thee shall no man lift up his hand or foot in all the land of Egypt.
May God bless your understanding of His word!