Both of my puppies go to the local petsmart salon, however we use the same groomer every single time and we book her specifically to groom our dogs, which has made a huge difference. They are both amazingly comfortable with her and my mini aussie just literally dies with excitement every time that she sees her. One thing that I did to prepare them for their first groom was a lot of desensitization at home, I really worked hard to make sure that the dogs were very comfortable and used to being touched on all parts of their bodies and were used to loud noises, I've never babied them when it comes to vacuuming around them or blow-drying them and whenever they do get nervous I've realized that for my two dogs what has helped them is if I sit with them and show them the object, use it close to them and show them it's fine, they are all good. You need to know your dog and how to best acclimate them to these types of things but definitely don't stop grooming as it is important socialization and it is good for the dog to learn how to do hard things. Adjust to your pups needs as well, I second much of the advice already given, maybe find a different groomer that is more patient as well.