There is a point where severe depression doesn't respond to the plethora of drugs that claim a 'cure' nor do you benefit from talk therapy. I speak from experience. There are currently 3 approaches, 2 of which focus on changing how the brain processes information in a physical manner. These 2 are electric shock therapy and trans cranial magnetic stimulation. Ketamine is a new drug that appears to to alleviate depression for many people but some providers get nervous over its addictive properties. Better to be addicted than chronically depressed. Find a good psychiatrist.