Am I the nightmare roommate?

My roommate (Liz) and I were random placement roommates at our small college. We met up a few times before we moved in and I knew I wasn't super fond of her but we could get along. The first week went by smoothly and then it started. Boy after boy after boy. One of them was a 28 year old (a decade older than her) that I told her I didn't want in the room because he made me uncomfortable. Usually most of the time I left while she had a guy over and I didn't mind but sometimes I wanted to be in the room and do homework and I didn't like him, he gave me weird vibes. Then, he turned out to be a weirdo like everyone thought he was and she went to the next boy. And this cycle of creep dudes coming in and out of my room was my world for the entirety of the quarter. Of course, I hung out with boys too and I don't blame her for that at all you do you; but the rate in which it was happening was concerning.

She was being stupid about it too. Taking 5 plan B's in the span of two months. All different people.

During finals of that quarter, Liz kept going back to this 28 year old dude, who kept hurting her over and over again. Frankly, I was tired of hearing about it so when she was talking about it I told her, "I really don't care, I've given you my opinion on this I don't want to hear it anymore" and then went back to working on my homework. Since then, she now barely speaks to me and I can tell she has a problem with me but I didn't really care all that much to find out what it was so I figured she would tell me at some point.

Now today, some boys that I was friends with called me and wanted to hang out. Liz was gone with a boy and had left her phone here because her mom tracks it. So, I said sure and they came over. We were all getting along when I noticed that one of them had picked up her phone and starting taking selfies on it. I asked them to stop, they did, and then I figured I would just delete them later.

Because her mom tracks her phone, I know the password to it incase she "needs me to pretend to be her" since she leaves it here so often. So, after the boys left I went to delete the photos off her phone and clean up the room so it was clean when she came back. When I was deleting them I noticed a text that said "(My Name) Julia is such a bitch!" I was confused to see it and without even thinking about it I read the text and the ones above it. It was paragraphs of how I am a whore, slut, every name you could call in the book.

Her and her boyfriend just continuously dragging me because I said I didn't want him to spend the night in our dorm room. Her 23 year old boyfriend and the most sketchiest person I've ever met btw. The same guy she is secretly dating behind her mom's back? Yeah I didn't want him to spend the night. She also calls me a druggie ( I only vape and smoke weed occasionally and usually not in the room) and made up a story about how my friend and I were forcing her to do drugs?

I'm just so confused and it went on and on and on. I have said nothing to her for her to feel this way. Since we came back from winter break I've been really focused on my work and usually just sit in the dorm with my headphones on doing homework. I know that I shouldn't have looked at her phone but this just isn't sitting right with me.

I don't know what to do.