I can understand why you feel this way, because the universe truly is so vast and complex that it staggers the imagination. And you aren't the first person to wonder about this; thousands of years ago, the Psalmist asked, "When I consider your heavens... what is man that you are mindful of him?" (Psalm 8:3-4).
And yet the Bible tells us that God is so great that He is concerned about even the smallest part of His creation -- including us. After all, God created everything in the universe -- even the smallest sub-atomic particle or the tiniest living thing. He also made the laws that govern their existence. But if He knows all about them, isn't it logical to assume that He also knows all about us? Of course He does. Jesus put it this way: "Even the very hairs of your head are all numbered" (Matthew 10:30).
God, however, not only knows about us, but He also loves us! Furthermore, He put within each of us the ability to love Him in return. Tragically, however, we've chosen to go our own way and shut Him out of our lives. The Bible calls this "sin" -- and because of it, we are cut off from God, both now and eternally.
But God still loves us, and He has provided the way for us to be forgiven of our sins and come into a personal relationship with God. That way is Jesus, who by His death and resurrection opened Heaven's door for us. Why not give your life to Him today?