Do you think i did the right thing i was just trying to protect my sister?

Well I'm 16 a junior and my sister is 17 a senior a year older than me she's deaf so she can only communicate by sign language we go to the same school and she has been bullied for the past year because of her disability. My parents never acknowledge it i always took care of my sister even though shes older. Anyway i keep getting into fights at school because they were making fun of my sister shes just a innocent girl i feel like as her brother its my duty to protect her from any kind of harm. Just yesterday i got into a fight at a school this dude was harassing my sister so i punch his lights out now i am suspened for 3 days i feel horrible but i really fel relieve that people know not to mess with my sister btw i am also a mixed matral artist did ido the right thing?