It might take a while, if he has a picture of your old way of fighting in his mind. He might be hearing what you are saying as critical even if you are saying it in a calm tone of voice. And it might not be as calm as you think it is, either. Just turning down the volume doesn't turn down the intention behind the words, and you might not have changed quite as much as you think. (I mean, look at your post's title. You are still trying to control him, it's just that now what you want to control is his 'perspective of your attitude.' Only when you give up wanting to control things about him, will you probably change how you come at him. At least, enough to make him believe it.)
It can take a while for you to reshape his vision of you just stay consistent and keep doing what you’re doing!