AITAH for beating up my ex best friend?

So back in middle school me and my ex best friend were already beefing. I was having a terrible day at school and lunch finally rolled around, I sat at my normal table like usual when I saw her walking up to my table. She leaned down in front of me with a smile on her face and calmly said, “your boyfriend is cheating on you.” And me being me I asked with who? And she looked me dead in my face with a SMIRK and told me my boyfriend was cheating on me with HER. So I stood up and walked to her side of the table yelling and screaming at her before I finally lunged at her. She didn’t fight back at all and I had gotten suspended for 4 days and she had pressed charges. Now here’s the thing, when I got back to school from being suspended she ran up on me while I was sitting down elbow to elbow with my friends. Aitah?