Is feeling violent all the time mental?

Okay I am 15 years old an I am constantly thinking violent thoughts I get mad extremely easy when I get mad I punch anything and everything in sight I just feel like ripping somebodys head off I went to a public school for one year an had to be home schooled cause I beat a kids face in with a fire truck cause he had the book I wanted and wanted to give it up ( I was 7) an couple days ago I took a water bottle an beat a kid in the head with it cause he was bugging me. My dad was worse then me at my age can this be genetic or mental? Dads good at controlling now though. Sorry for it being to long. Thanks!!!