I've read a LOT of these books. And there's a few in CBT that are helpful (including this one). There's DBT. There's practical self esteem work (confidence is repeated domain specific success). There's some philosophical work that helps. Lifting heavy weights helps. A blood test from privatemdlabs where you can see everything inside you (if you can afford it) helps. Nutrition helps. Sleep helps. Etc.
But feeling good, which has to be 20 to 30 years old, by far is the most effective thing I've ever seen.
Pro tip: type up the excersizes (or google them) and try journaling them into an evernote. The progress is 10x faster. 2 months of feeling good probably did as much as a few years of weekly CBT counseling.
Strongly recommend.