AITA for yelling at my lover for letting her best friend make me uncomfortable in my relationship

Recently I (19F) got into a relationship with my coworker Lyla (19F), she’s an amazing woman and I love her dearly but her best friend Olivia (18F) is the worst person in the world her best friend trauma dumps and uses my partners insecurities to keep her as her friend, my partner even told me that her friend had a crush on me and asked if we could become a throuple which obviously I said no to, Lyla and Olivia are really touchy like link arms and walk around touchy. It makes me feel so angry, I mean Olivia used to have a crush on Lyla too??? And sometimes they will whisper and talk to each other when I’m right next to them and when I try and join into the conversation they just ignore me. I’ve been told it’s because my girlfriend is scared of me arguing with her about the conversation which is insane because we’ve only ever had one argument in the past 6 months and it was about abortion. I talked to my girlfriend about these things and how close her and Olivia are make me feel bad because Olivia used to like me and her and she just said "I can understand why she likes you" as if I wasn’t trying to be reasonable, I kept talking to her and asking why she did things like this, why did she continue hanging out with Olivia if she knew that Olivia would attempt to hit on me, why she let me feel uncomfortable in my own relationship, I feel bad about it but I brought up our past fight and how she was defending something that was wrong again. I guess I pushed too far and ended up shouting at her because she started crying, I comforted her but I ended up still getting pretty heated. I tried talking to her again a few hours later but she just ignored me and drove to Olivias house. Olivia texted me this morning calling me a horrible person and that I should give up on this relationship And even if I don’t give a rats ass about what stupid Olivia thinks she says I was being an ass hole. I just need validation that I’m not being crazy about this and I feel bad for making her cry