I'll agree with you on that last part, Katie--it's the entire premise of St John of the Cross' dark night of the soul, which you can find
online.
That being said, it isn't the usual cause of feeling seperated from God. Now, I don't know, maybe you're a better Christian than me or something, but in my case, it's almost always that I don't want to hear what God is saying. I try to fit him into a neat little box, and when he doesn't fit into that box, i unconsciously ignore him. It's entirely possible that God is being silent in order to teach you about faith, but it's equally possible that it's something in your heart keeping you from hearing God. We're not judging you--it happens to all of us.
If you're feeling abandoned by God and you don't mind some reading, try Hosea or Malachi. They're both pretty short and in the old testament. Hosea is the story of a man God asked to marry a prostitute, to demonstrate God's unconditional love for his people. Malachi is written to a nation questioning God's love for them and his justice, believing they have done nothing wrong. It's a personal favorite of mine, because it always helps me see my life from God's perspective again.