Heal the illness. As the depression heals, enthusiasm, well-being, and a sense of life's purpose will return. It is the feeling that nothing is worth while that makes men ill and unhappy. You didn't do anything to become depressed. Your failure to do something didn't cause your depression.
Depression is an illness.
You are no more at fault for having depression than if you had asthma, diabetes, heart disease, or any other illness. In becoming depressed, you have nothing to blame yourself for and nothing to feel guilty about. A predisposition toward depression can be hereditary. So, for heaven's sake, don't blame yourself. Don't even blame yourself for blaming yourself.