So you're saying God the Father had a mother, eh?
Not only that but He had to fill Himself with the Holy Spirit also.
John 3:34 For he whom God hath sent speaketh the words of God: for God giveth not the Spirit by measure unto him.
If that doesn’t help you understand that Jesus was fully and separately a human there are other verses to back that up. While there is no way for us humans to fully comprehend the true nature of Christ and the relationship of His two entities we can be assured that God did not have to give the Spirit to Himself.