DS1's temper is driving me to despair (6yo)

[mydoorisalwaysopen]

My DS1 aged 6 nearly 7 is driving me to distraction with his temper. He blows up over the smallest thing, sometimes over nothing at all. He trashes his bedroom, becomes violent, throws toys etc. Even when he is calm he will absentmindedly kick his brother (3 nearly 4) or chuck things around. I am trying to teach him to calm down and to respect his home and belongings but I am severely tested by this. It is really bringing me down.