Aquinas's third argument for existence of God

I'm currently reading the textbook Core Questions in Philosophy by Elliott Sober. I've had some ideas about what it discusses prior to the discussion about Thomas Aquinas's third argument for the existence of God, but I'll save that for later (if ever) and start with what I've read today.

Aquinas's third argument is about contingency. I disagree about what is contingent. According to my book, you, me, the human race and the galaxy are examples of contingent, or unnecessary things. I would say that I (or the self) am a necessary being. The universe would be empty without me. The universe is also a necessary thing. The universe is two things: the totality of all things in the present, or what is going on in my mind in the present. The latter is more true, because there may not be anything outside of my mind. If nothing was going on in my mind, I would be empty. I would be empty without the universe.

I believe that there are things to live or die for, though.

I also believe (and I jump ahead in the argument for the existence of God) that there are levels of need that God has. I think the first thing that happened that Christians believe was that the Son was begotten (not created) from the Father.  (Or maybe was among the first things, I should say.) Then God created the universe. I believe that God had varying levels of need for different things that God created (or maybe even begot). I believe that God wills some things to varying degrees, and I believe that creation can will some things to varying degrees too.

I'm going back to reading again.