Get a trainer. YOu have to be careful, this fear can turn into fear biting soon, a trainer will help you to prevent that....not too much online people can do. Dog needs to be evaluated, and have a program put together the fills it's specific needs. Plus, it's just safer to get a trainer in real life with an extremely fearful dog. You don't want to make it worse by implementing something you read wrong, or just getting plain bad advice because no one here can see the dog. There are lots of threads about fearful dogs that you can read, but ultimately you should seek a trainer.