Ummm. It never really goes away. You can learn to live with it though. Diet and exercise work well. Actively embracing hardships. Start small with all of this. Small wins turn into bigger ones. I hope you can get through this.
When you are depressed your emotional and physical activity slows down or may become inactive and since you cannot be fast enough for the society it becomes more and more difficult to keep up thus creating depression to get out of it you have to force yourself being active at all times.