Huge friendship problem...HELP ME!!?

I have had a friend named Lauren for about 1 ½ years. Occasionally we get into arguments. Now, we are both in Middle School and I met a best friend named Alex (it’s a girl). But the problem is that Lauren hates Alex for no reason. So today at school it got ugly. On email in our typing cl, Lauren emailed me and said, “I don’t want to talk to you anymore.” So I emailed back asking why. She said “just because you like Alex more than me”. She always glares at Alex and refers to HER as “him” even though Alex is a girl. I asked Lauren why she said that Alex was “him” and she was like, “I can say what I want…u got a problem with that?” Also on her email signature, during cl today she changed it and now it says, “I love all my TRUE friends…the ones who have never gotten into arguments with me before.” It really hurt my feelings. She also emailed my friend Ellie and said “You are my TRUE FRIEND because you have never hurt me before.” Ellie sits right beside me and I saw the email on the screen and I got upset. I think Lauren meant for me to see it too. Ellie replied back saying AWWW thanks!! Also, Ellie and Lauren have only been friends for about 2 weeks. lauren replied back saying, “ILY sooo much!!!”. My feelings are extremely hurt by Lauren and I don’t know what to do. Can anyone help me? And I promise this is true. Every single bit of it is the truth.