
Cognitive Behavioural Therapy For Dummies, 2nd Edition will help readers identify negative and unhealthy modes of thinking which have been holding them back from the changes they want.
https://www.amazon.com/Cognitive-Behavioural-Therapy-Dummies...
Ignore the stupid series title, it's a great book.
The tl;dr version is that you can (and probably should) step back from your thoughts, observe, and experiment with them to tackle your own negative or limiting thoughts.
I think that CBT will probably appeal wildly to the autodidactic HN'ers than pop up here. Check it out, even if you decide on another book.