[ADanFromCanada]

My suggestion would be to think of confidence as if it were a skill and, like any skill, practice makes perfect.

The fact that you have recognized an area of your life that you want to improve and even specific situations where you know you can/want to work on it is half the battle. The other half is making a conscious effort to be more confident and less shy when these situations arise. Part of this is fake-it-til-you-make-it, and part of it is re-wiring your brain to be open, communicative and confident in these situations instead of shy and/or anxious.

As far as a book recommendation goes, I read a neuroscience book (written for the layman) that while not dealing with this topic directly, will definitely provide you the knowledge and understanding of how to improve. It's called "The Brain That Changes Itself" by Norman Doidge. It's about neuroplasticity, how it works and how you can use it to change your habits, behaviours & skills.

This has been one of the most impacting books I've read in my life. I have purchased more than 10 copies for family and friends and everyone who has read it has come away amazed and able to make almost any positive change in their life.

Cheers & good luck!