My wife's a psychologist and depression is one of her specialties. Here are her recommendations:
Self-Therapy for Your Inner Critic book
Free guided meditations for "The Mindful Way Through Depression" (get some practice before using "working with difficulty" meditation): streamable or downloadable
And the associated book
Please let us know how it goes.
If it's worth saying, but not worth its own post, even in Discussion, it goes here.