Question about anger, am i normal?

im 16 years old, of italian decent (Sicilian and Calabrese) i have a very bad temper and get mad at the littlest things. i get so mad that i just want to punch a window or a wall, i guess because when i get mad i feel like i have no feeling, like pain would feel good, (i dont cut myself and have never broken a window or put a hole in a wall) i just get so mad, so mad that i dont know what to do with myself and i dont let it go and i dont know how to let my anger out because at first i dont let it out i just let it build up. all those times i get so angry and frustrated i dont let it out i take it in and then ill just explode, is this normal? just please help me.