Avoiding a Friendship

Hello all!

I have a problem that is probably different than what is normally seen in this forum. I actually want to avoid being friends with someone. Normally, I don't have this kind of issue because it is difficult for me to make friends. However, I do have friends, and I love them all. I am very particular about what kind of people I let into my life because in the past I made the mistake of letting toxic people in, so I'm very vigilant about red flags. This girl is someone who was in my major in college (which I just graduated), so we had been forced to work together before. I did my best on the projects we worked on, did most of the work, and we got A's, but she would still complain about me to other classmates behind my back because I wasn't doing the work the way she wanted. She has no idea that I know this. She also made nasty comments about our classmates relating to their sexuality. She is very controlling on every project I have ever worked on with her or seen her work on, and seems to be envious of me in a lot of ways. She would look at me a lot in class with a resentful expression and would make comments about the clothes I wore, which would indicate she was jealous. I purposefully tried to distance myself from her and was only ever cool and polite when we had to interact out of necessity. I also avoided ever seeing her outside of school. I thought I would never have to deal with her again once I graduated but I saw her at a friend's place.

The problem is, as much as I dislike her, and as much as she seems to not really like me, according to my friend she really wants to be friends with me, which explains why she was always inviting me to things. She also tries to be on her best behavior around me, though I can still see her flaws. Frankly, I have no idea what I did to make her want to be friends with me. My friend also has trouble dealing with her, and has decided to just invite her to things out of courtesy. I am unwilling to go that route, because I don't think I could fake being happy around this person that long. And I'm planning on going to an event this weekend, where they will likely be, but I am adamant about going because I've been really looking forward to this event.

Whenever I'm around her, I feel sick to my stomach and my hands shake. She makes me genuinely uncomfortable and anxious, and I have no desire to be friends with her, but I also don't want to tell her that directly because I don't want to deal with the fallout (as she is very dramatic) and have that spread around people I know and like from college. Should I continue with the tactic I've been using of avoiding her and being polite? I probably won't see her much, since I did just graduate, but if I see her at this event I don't know how I'll deal with it. I'll probably freak out internally.