Me(f17) and my brother (M18) just got into a screaming match because he didn't understand why our mother (f57) was upset after we got back from prom.
A little context, our mom has been through 2 abusive husbands before my dad and then she left our dad because she thought he was going to be abusive, she worked 2 jobs to make ends meet afterwards and me and my brother were raised by our sister for a few years. To keep it short, she has sacrificed a lot for us. Our mom came in and said our aunt (f65) didn't want us coming into volunteer today, my brother proceeded to get angry asking why and my mom went on a long mom rant about how we excluded her from our prom experience and i was going to get ready with my aunt and my mom. Well, my best friend called and asked if i wanted to spend the night and get ready for prom together, my mom said yeah and is now blaming us for my aunt getting upset. My aunt doesn't have a daughter of her own so i wanted to have her help me get ready so she could have the experience. Keep in mind Me and my brother both are autistic, higher functioning.

Back to the point, my brother doesn't appreciate anything our mom has done for us and is saying shes the asshole for getting upset. I kept asking him to please go back into his room because i do not want another screaming match. He kept refusing over and over again. That lead to us screaming at each other, me saying hes an ungrateful immature brat that cant see that he has everything handed to him on a silver plate, him mainly just getting upset screaming because my mom corrupted me. My brother has always been the favorite, whenever in conversation he would interrupt me multiple times and my mom wouldn't care but when i interrupt her precious baby boy i get screamed at and yelled at. My brother now sees this and gets mad at her anytime she shows favoritism. my throat hurts from screaming, i love my brother and my mom i just dont want anymore fighting. AITAH?

Edit: a little more context my mom isnt the best mom in the world she blows things out of proportion a lot but like that still doesnt give him the right to talk to her like he does