I'll add a few book suggestions.
The Cautious Canine by Patricia McConnel
Scaredy Dog by Ali Brown
Focus not Fear by... maybe also Ali Brown?
Click to Calm by Emma Parsons
These might possibly all be ordered through vendor's websites that help with the finances for this forum.
When looking for dog classes to help your dog, ask if they have "Reactive Rover" classes, "Feisty Fido" classes, or even some Scaredy Dog seminars may be in your area. Emma Parsons does seminars here in Massachusetts (Click to Calm) as well.
Grimm van den Heuvel, "Donnerpratzen"
Smokey The TeddyLion, DLH purrbuddy
Dir gehŲrt mein Herz