I think that “doubting thoughts” are a universal human experience.  But doubts can be an obstacle to the healing process.

I can tell you how it was for me when I was healing.  My own doubting thoughts were trying to protect me from disappointment.  If I kept doubting, and didn't get my hopes up, then I wouldn't be disappointed.  Logical, but very self-defeating.  I finally came to the conclusion that I would rather take the chance on feeling disappointment.  I could survive that.  It would be upsetting for awhile, and then I'd pick myself up and try something else.

So, I decided to take the leap and trust the therapist and the cognitive-behavioral program I had found.  I committed myself to the program and to learning everything I could from it.  When the doubts came up, I told myself that I was willing to pay the price of risking disappointment.  Risking disappointment was a small price to pay for my healing.