My best friend told me off today and she has NEVER been this brutal me. Should I be mad?

OKAY so two weeks ago, one of my best friends caught me kissing her boyfriend and she is HURT and hasn't spoken to me since. I tried to show her how sorry I am. I pushed her boyfriend based after she caught us. I have been called her and texted but nothing! My other friend uninvited me to her wedding which was last week and I ended up missing it because I'm now untrustworthy.
My best friends told me off, "If you were a true friend, you wouldn't have kissed my boyfriend! That was no accident. How do you think I felt?! You were stupid enough to kiss him when you could have just back off and now I CAN'T TRUST YOU ANYMORE!!!! THE TRUST IS GONE AND I WILL NOT BE FRIENDS WITH SOMEONE THAT KISSES HER BEST FRIEND'S BOYFRIEND BEHIND HER BACK!!!!!!!" I won't tell you the other thing because it's very brutal. I had that shocked look on my face and I could not say anything. She hung up on me and cut all contact from me. We've been friends since 1998. 19 years and she is just going to cut me from her life. What did she had to act all hostile to me?!