Yes, every human being has an essence which belongs to him, and a body and soul which is expressed as an individual person—a subject, an “I”
Perhaps there is some confusion about the idea of creation ex nihilo. We are not products of God’s imagination.
A human being, for example, might imagine something which has an essence but no existence. I might imagine an intelligent pink unicorn. I might endow the unicorn with a complete but imaginary physiology, anatomy, and social interactions which I can describe in detail. I can write a book about his world in great detail. Still, the unicorn and his world lacks existence, because I do not have the power to give it to him. He is a product of my imagination, an essence with no existence.
But God, to put it little strangely, has no imagination. He creates the universe and all that is in it from nothing, and gives it existence—something we could never do. He gives it a real and permanent existence, not an imaginary existence, an existence separate from his, for we are not made from God but from nothing. But it is a created existence, not an uncreated existence.
In any case, God has no parts from which he might construct us or the universe. And if he did, he would diminish himself in making us. No, he makes us entirely of nothing and entirely distinct from him, giving us a real existence, and the ability to know, to decide, to love. Nothing he makes is imaginary. It is all real. We have a real but created and contingent existence.