It is painful-----------but, like some other painful medical procedures, it might save your life if you tolerate the side effects...
The darkness is there---if you don't walk through it, it will take you by impulsive surprise & that can really be deadly....
And, it will seem, for a time, that all is darkness, but you wait, and you put one foot in front of the other, and some good things, a light shines, as you move through the repeating shadows...