Why do i do this while sleeping?

Soo I'm 14 and for the past 2 years I've been sleep walking.. and my brother and parents tell me while I sleep walk I'm always swearing, and when they say something to me while I'm sleep walkin I flip out,and I also throw all my bed sheets off my bed, then go check my phone. Also my brother tells me I punch my bed he said when night I said "I'm tired of motherf***ers jockin my style and I started beating up my bed,and the other day I woke up with no clothes on