You've already a good start by taking some deliberate action. It is good advice from Jim11, and there is a lot of good info on this site.
However I will recommend that you first read Frogs into Princes by Bandler/Grinder
The book is the original introduction to NLP, and NLP is a great tool for understanding how your brain works, and to use this knowledge to change yourself (and fast) - especially (in my opinion) to 'theoretically minded' persons.
Let me know if you want to know more about this :-)