My puppy keeps yelping very loud at the vet, how can i help her stop?

im taking her to get her shots and the first round was fine, she was really young so it was okay. 2nd round she squirmed and yelped on the top of her lungs and peed on the vet table she was not as bad as today because the worker was so nice. 3rd time i went today and this mean worker grabbed my puppy by the scruff and dragged her out as my puppy was screaming. then she started yelling at us to go away and that we're making her yelp more. so we stood off by the side while she was yelling bad dog at my puppy while shes screaming and peeing like super loud. that worker was so mean, this is the humane society btw. and my puppy cried all the way home yelping until her voice was hoarse. i brought treats and toys but once she goes into that room she gets so scared. especially with that rude worker!