Saffie, Cognitive-behavior therapy is a useful tool for the reasons you mentioned. I think it has it's limitations, but it's a useful tool to help with countering negativity and self-defeating thought patterns. A book written by a CBT therapist that is accessible is Breaking the Patterns of Depression by Michael Yapko.
CL
CL 53 W 54 M 20 yrs. 03'-09' Separation + Old Patterns + GAL 10-14' Piecing
"The Master allows things to happen. She shapes events as they come."
