During any period of crisis or extreme stress, it s common to experience frightening feelings of disorientation. Anxiety can be so generalized, you can't even put your finger on the exact cause. It feels like your brain is going to fly apart, and you might feel lost and confused most if not all of the time.
Mental concentration is only a vague memory.
Last year you could read a book and enjoy it. Now you read the same opening paragraph seventeen times, and still have no idea what it said. That's not just scary. The thoroughly capable person suddenly feels incapable. You feel crazy and stupid, and the worst part is that you think you may feel that way forever.