CBT is wonderful imo. It isn't a get well quick therapy (not brief therapy) though you can take the basics and begin feeling better by countering the negative thinking, rather soon.

What happens with CBT, imo, is that over the course of time you change the habits you have fallen into. The negative thinking, the irrational thinking, the perspective of life and world that has become distorted, all those are adjusted by learning and practicing CBT.

Sometimes bad habits began because of how others treated you, what others have told you over and over ( that being negative and perhaps abusive) and are not easily recognizable except by a Therapist.

Things you do, the way you "are" often are because of unconscious training. This behavior might not be in your best interest. Working with CBT you find those areas of your life that are mine-traps and correct them.

CBT is definitely work! It takes looking at yourself and seeing plenty of negative issues, and working through those to realize it isn't you... it's what that type of thinking has done to you.

TC!