I need dog sedatives?

Two months ago, my fiance and I took in a dog from a friend. She is about six years old and they found her tied up on the side of the street. Her shots and all have been updated, but her nails are TERRIBLE! They get caught in absolutely everything and she screams or the break off. However, I am in the process of finishing school in a few weeks with no job, and my fiance is holding up rent and gas - therefore, we have no money for high-end vet bills right now. We have enough for the ten dollars for her grooming. Without a muzzle, she bites every groomer. With one, she squirms and screams and it can't be done. How can I get sedatives without getting another checkup at the vet?