The best thing you can do to help a dog overcome its fears is to teach it to pack-walk. Walk him every day and ask him to heel and respect those around him. Showing a dog leadership will help him feel secure. Dogs really want to know what to expect, who is in charge and what the rules are.
Giving a dog that type of structure is the best way to help him overcome a lot of unnatural issues. Do not feel sorry for the dog or he will sense your feelings and it will make him unsure. The humans around the dog need to be strong-minded so the dog can relax and not worry about who is going to lead. Learn how to speak dog so your dog understands you and you understand your dog.