My brother just punched me?

i was trying to go downstairs and get brownies and talk with my family, and i don't know his problem but my brother is always mad at me for taking the attention away (my parent's mostly spend time with me) and today he was exceptionally mad and decided to punch me as hard as he could in the throat. he's smaller than me, but it still really hurt and i can't move my jaw and my nose is bleeding what should i do? i'm fine now, but it's just my jaw that hurts.