Hey guys. I need some dog psychology.

We have two toy poodle pups with about a month difference in age - they're about 6 months old now. Pretty early on (at about 3 months old), the younger puppy was injured during play with the other dog. She needed pain medication for a few weeks while her muscle injury healed. Before the injury she was outgoing, energetic and playful, but since then she's become extremely nervous and inhibited. She's gone backwards in her toilet training, doesn't engage in play, doesn't always eat her food, and is extremely afraid of most things (e.g., a loud birdcall outside sends her sprinting back into the house, runs away from other unfamiliar dogs etc). I can completely understand why she's become so nervous - it makes sense for a traumatic early-life injury. I am just wondering if anyone has any advice on how I can build her confidence again. I've tried rewarding her for times she even chews on or paws at a toy, tried mild exposure (e.g., sitting with her and calming her while there are loud noises or other dogs nearby), and tried changing her food a few times to see if that will encourage her to eat.

Any help is appreciated!

pic related, it's her.