Only in his humanity is Jesus separate from His Father, yet still equal to God in his eternal deity as the Word!
1st John 1:1
“That which
was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of
the Word of life; (For the life was manifested, and we have seen
it, and bear witness, and shew unto you
that eternal life, which
was with the Father, and was manifested unto us

”
He was
with the Father as far as being
ONE with Him in His eternal Deity as God blessed over all. Jesus was the God of Genesis 1:1 as the Word of God! They were
ONE as far as what consist of real Divinity of the Most High God?
The following attributes have ever been conceived as essential to it:
Self-existence, Infinity,
Independence, Omniscience, Omnipotence, Omnipresence, Immutability,
eternal both ways, and Infinite in every way possible that is imaginable to the human mind. Deny any of these attribute concerning our Lord Jesus Christ, then one has rejected God's testimony concerning the Godhead. To do so is antichrist.
I'm sure it is to you and your Catholic source of information from the Nicene Creed. We will never use Creeds written by men to support our understanding.