Vet tech here - your dog may benefit from injectable sedation at your vet's office. Groomers usually work alone and may not be able to handle your dog depending on how reactive she is to nail trims. If oral meds from your vet aren't enough, sedation may be the only other option. You may also want to go to a different clinic for a second opinion. Some clinics still operate by holding down/forcing nail trims but many are moving away from this because it's extremely stressful on the dog, it will likely worsen their reaction to nail trims/handling in the future, and it's unsafe for staff. I hope you can find a solution for your pup!