How do I cope with co-worker talking behind my back?

I’ve only been at this job for two months and already gone through workplace drama with this woman named «Mary» (false name) I’m still learning new things everyday but mostly I can work independent as I know how the system work. I’m taking this job seriously and I’m doing my best everyday to exceed the goal that me and my leader have set. It’s a long story but having context would sure help. Mary, which had the responsibility for me when I was under training had been taking workplace stress out on me saying rude words. I also did not feel that I got the help that I really wanted under training and I have to think about myself to gain information and learn as much as possible so I asked my manager to switch person which was way more helpful and I learned alot under training so that I can work independent when the training was done. A week after Mary was talking about me behind my back. Saying things like I should get a new job because I’m stressing, saying that she wants me to take more calls. I work in callcenter in a open office landscape. I did not think much but got it confirmed when I asked my colleagues what’s up with people whispering. It’s not okay for me when she already started talking behind my back and it has not been 1 month!? Last week there was an episode where she screamed at me saying that I need to help out before there was a line of people waiting. I could not keep staying quite so I stood up for myself saying «you don’t have to worry about me. You do you and I do me. After this episode my manager had a seperate meeting with us. From what I understand Mary is frustrated about how I do my work. While I’m frustrated about her whispering and making the workplace toxic. I do my work as I should but she doesn’t see that and I’m not going to convince her and show her that I take it seriously. She’s not my manager so who is her to tell me to do this and that? I think it’s worth mentioning that she has been working there for 1 year and previous employees were lacking so Mary has had bad experience with male employee that are new but is not an excuse for her to treat me like this. Today I overheard her saying to a new employee «He just took two calls and that was it» and the new employee said «yea it seems like there is alot to do today». The new employee might just follow the wave but I do not think it’s okay for her to keep doing this. I come to work feeling burned out and feel less comfortable sitting there with the rest of the team.