I am confused by your analysis. You say the depression is your mind reacting to the fear and panic as a way to protect itself. If the fear is alleviated your mind has no need for the depression. Why do you assume your mind will stay permanently emotionally shut down. This thinking is not very scientific.

From a scientific point of view depression and anxiety and panic often go hand in hand. It is very hard to sort out which causes which or if they just come as one big clump. A professional would seek to treat both the anxiety and depression at the same time. From a scientific point of view it is proven that many people do overcome depression and anxiety and once again perceive pleasure. You seem to have ruled this totally out as a possibility. To say it is impossible for you is not logical. You do not know the future and you would have to try all the available options.