<human>: Can you summarize the given text in a few sentences?

There's a girl in my masters program that has been making my life incredibly difficult. This wouldn't be an issue if she left it at that, but she can't seem to decide whether she hates me or wants to be best friends. Since day one she decided she did not like me. She would call me a bitch in front of professors, constantly call me out when I'm not even interacting with her, and consistently made me feel bad about myself. She's attractive and pretty fit, I'm kind of on the scrawny side, and yet she frequently would tell me I don't know what it's like to have difficulties, because I'm thin. I tried to make the situation better by inviting her out one day, and the first thing she said to me when we met up was "you know what really pisses me off about you? You've probably never had to take public transportation and everything was always so easy for you." This really hurt, because I try so hard to appear as if everything is okay on the outside, but I have PTSD from an abusive childhood and some pretty anxiety. Since then, she continues to call me a bitch, says really mean things to me, but asks to hang out all the time. Last week she told me "not to talk to her like that" and then the next day invited me to a girls night she's hosting. I've politely declined her attempts to hang out after pushing things too far a few times, but yet she still tries to be my friend. I'm so confused and don't know how to respond to someone like this.
<bot>: classmate consistently calls me a bitch and is mean to me, but keeps trying to hang out with me even though I continue to decline.