I have had coon hounds, beagles and bird dogs for 45 years now. I have never seen one yet that was "cured" or "got over it". You are wasting your time with this dog. I know you don't want to hear that, but in about 6 months, if you are honest, you will admit it to yourself that this dog was a waste of time. As already posted, these types of dogs have a soft personality. It was born shy and it will always be shy. It just takes the right event to bring it to the surface.
What you choose to do with the dog is your decision, but whatever you choose you will learn it the hard way. When you finally do get over it {you, not the dog} you need to think about if you want to try again and if you decide to have another go at it then you need to harden yourself to the fact that not all dogs make it and life is too short to waste time piddling around with a half dog. Demand perfection or you will never have it. The surest way to know if a man is a liar....he will claim to have cured a gun shy dog. He will probably even show you one that is not gun shy and say, "see". That just means he lied twice!!!!!!!
