The Unheard Cry for Meaning by Viktor Frankl is a wonderful book that combines humanism with self help and psychotherapy. Addressing our angst and search for meaning and it’s impact on our mental health. And he does this all from an explicitly Humanist frame of reference.
In these selected essays, written between 1947 and 1977, Dr. Frankl illustrates the vital importance of the human dimension in psychotherapy. Using a wide range of subjects—including sex, morality, modern literature, competitive athletics, and philosophy—he raises a lone voice against the pseudo-humanism that has invaded popular psychology and psychoanalysis. By exploring mankind’s remarkable qualities, he brilliantly celebrates each individual’s unique potential, while preserving the invaluable traditions of both Freudian analysis and behaviorism.
That blurb sounds way more technical than this book really is. If you have existential angst or really anxiety of any kind – read this book.