Do you ever wonder if King David was a happy person? I'm serious. His Psalms are so full of Anguish and grief, its easy to think that this guy was a Bronze Age candidate for Prozac. Over and over again, they repeat how his enemies are after him, how the anguish resulting from his problems is too much for him to bear -- even wondering why God hasn't answered his prayers.
Reading the Bible stories about David, however, you get a totally different story: when he was young, he was a warrior who faced his problems head on, who was willing to show emotion, but always faced his enemies with the knowledge that God was with him. As a mature man, he had to live with the results of His sins, but he had the faith to know that God would never forsake Him. You don't get the impression that the king walked around moping all the time.
I'll tell you a secret: I am sick and tired of listening to people tell the suffering that they're not Christians if they're sad, doubting, depressed, or feeling alone. If you read the Psalms, that stuff's all over the place. It seems like one difference between a Christian and non-Christian is that the believer has Someone to share these feelings with and Someone to help us through them.