I'm thinking of quitting dentistry forever

Hi, I'm a new graduate of dentistry school. I graduated 6 months ago and immediately started working. I honestly think I'm terrible at my job, six months and I still don't see any improvement, my hands and heart shake every time I have a patient on the chair, I have zero confidence and I make a lot of mistakes, in these six months I broke two files and I'm also terrified of molars, my work isn't good and most of the time I work under pressure and I just want to finish and that makes me incredibly guilty...I feel like I'm betraying the trust that people have put in me so I think of quitting... Maybe it's not for me, I feel like I'll never be good. My boss keeps yelling at me and she absolutely thinks I'm bad and I don't blame her honestly, I'm tired and scared and I feel like a failure, I genuinely feel so horrible right now. (I'm sorry for my bad English)