You lack understanding of who Jesus is! Deut.18:18 is part of the story.
Not part of the story but the fulfillment of the story.
I know who Jesus is and I know who he ain’t. Jesus ain’t God. Jesus prayed to God for strength. Kind of weird if God incarnate did that.
The obvious proof that Jesus is not God is that Jesus died. The story continues because God, in his unitarian nature, raised the lifeless corpse of Jesus. Jesus did not raise himself from the dead.
The resurrected Jesus told Mary he had not yet gone to his God. Jesus has a God. Jesus’ God is my God. He alone is the only God.
Jesus alone is our only mediator to God.