Get him in some obedience classes. That can hopefully give you and him confidence. I would not allow him off leash for his own safety. If he is truly afraid, his state of mind is not a good one.
Misty- Samoyed Mix, Tannor- Golden Retriever CGC
Robyn- GSD CGC, TC, Midnite-GSD CGC,TC, Brennan-Golden Retriever CGC, Batman-Husky/Greyhound , Apollo-GSD