英语短文改错!10处错误!

When I (grow) up, I want to be a musician. I (won't) mind (playing) any instrument and I will be (contented) (so) long as I become a musician. (However), I love playing the piano becuase (playing) it always cools me (down) when I am angry. I (have been) wanted to be (a) musician since I was 5.

When I grew(grow) up,I want to be a musician.I wouldn't(won't) mind in(X) playing any instrument(加S) and I will be content as long as I become a musician.But,Ilove playing the piano because play(+ing) it always cools me up(down) when I am angry.I have wanted to be(加a) musician since I was 5.