Bear in mind, that as she's clearly widely unpleasant, you won't be the only one experiencing this so you drawing away, while she might yell a bit about it, might well actually allow other people to feel comfortable doing the same.
I am a lot older than you but went through this exactly in my first year at uni. A girl who lived in my residence and I struck up a friendship, along with a number of other girls. But she turned out to be a complete cow who was mean to me and to everyone else for no reason. So in my second term I started avoiding her, and I admit, it was hard as I didn't have anyone to replace her and that crowd as my friend. But... at the end of the second term, things got better and by the end of the third term I'd met some wonderful girls, a number of whom are still my friends today, and one will be my bridesmaid in just a few short weeks.