Viktor Emil Frankl M.D., Ph.D., was an Austrian neurologist and psychiatrist as well as a Holocaust survivor. Frankl was the founder of logotherapy, which is a form of Existential Analysis, the "Third Viennese School" of psychotherapy.
His book Man's Search for Meaning (first published under a different title in 1959: From Death-Camp to Existentialism. Originally published in 1946 as Ein Psycholog erlebt das Konzentrationslager) chronicles his experiences as a concentration camp inmate and describes his psychotherapeutic method of finding meaning in all forms of existence, even the most sordid ones, and thus a reason to continue living. He was one of the key figures in existential therapy.
Read this book, be sure to read it. At least what you get out of it is that you realize that people are still able to go on living in their worst mental and physical conditions. That the meaning of our life is beyond failure and easy giving up, and that there are people who touch the darkest part of this world and still believe in its beauty.