There is a reason people sometimes can’t simply “pull themselves together” when they have fallen into a deeply negative emotional state, and it has very little to do with weakness, laziness, lack of willpower, or not wanting to feel better badly enough.
The problem is much more paradoxical than that.
You need energy to change your state. But when you are in apathy, hopelessness, fear, or prolonged negativity, energy is precisely what you feel you don’t have.
In other words, the very thing you need to climb out is the thing you are running short of.
A classical Catch-22.