The three persons of the Trinity (Father, Son and Holy Spirit) are eternal, and equal. While they are individual persons, they are the same God. Jesus humanity came into existance in time, but His divinity is eternal.
What it is hard for us to conceive, and many misunderstand it, or even teach something else, Jesus is 100% Man and 100% God. Not 50/50. As the Creed tells us He is True God and True Man.
One of the problems we have with the Creed, be it translated into traditional english, or modern english, we are limited by it being a translation. Since it was first written in Greek, and translated nearly immediatly into Latin, the term we see in english as hell, does not mean the hell of the damned, but rather the waiting place of the Fathers, those who died before the crucifixion, awaiting the redeeming actions of the cross. There are many words which when translated into a living language like english can have different meanings, this is just one example. It is also why I enjoy the study of the faith, because there is so much one can learn, the Truths Jesus taught and the Apostles handed on to the Church can fill your life with so much richness, that there is always something new to learn.