John Piper has a wonderful little e-book which I've just this morning discovered - and have read half of already. It is called "When the Darkness Will Not Lift: Doing What We Can While We Wait for God - and Joy" and it is available, free, through the Desiring God website.
He discusses the problem of spiritual darkness and depression in a child of God, and what to do, how to pray, and how to keep your eyes focused on Jesus during your seasons of doubt. Most of us have experienced a "Dark Night of the Soul" at one time or another, whether it was brought on by the bulimia, another addictive sin, or has a more ill-defined origin.
An excerpt from the book:
"Gutsy guilt means learning to live on the rock-solid truth of what happened for us when Jesus Christ died on the cross and rose again from the dead. It means realizing that in this life we will always be sinful and imperfect. Therefore in ourselves we will always be guilty. This will prove emotionally devastating if we do not discover the reality of justification by faith, that is, the secret of gutsy guilt. This is not the only weapon with which we fight for joy in the darkness of discouragement, but it is one of the most foundational and the most important."On forgiveness when we confess and turn from that sin that's blocking our fellowship with God:
We can hold fast to our sin, keep it secret, and “groan all day long” in darkness—or we can confess it and experience the stunning experience of “the man against whom the Lord counts no iniquity.”
The almost incredible hope of confessing and renouncing sin is that the Lord does not then rub it in our face but cancels it. He does not count it against us. From this side of Calvary, we know how God can do that with justice. Christ bore the wrath of God for that sin (Gal. 3:13). We don’t have to. The accounts are settled. Therefore, we should not fear to confess and let go of any cherished sin. The shame will not haunt us. Christ clothes us with his own righteousness (2 Cor. 5:21).
It only takes a second to download, and I highly encourage you to prayerfully read it - you'll be blessed!