You didn't do anything wrong. I have the exact same situation with my boy.
If anything, we did too good a job raising our roosters. They are fine protectors and superb roosters-- very virile and protective of the hens. We taught them to do their job.
From what I have fathomed, it's the sweet, good little boys who grow up into these aggressive, vain roosters we have. The roosters who are neglected and not showered with Tender Loving Care turn out to be bland, boring grown-up roosters who have no personality much.
I think we gave our boys extremely high self-esteem, and they feel so good about themselves that they have become narcissists.
When my boy gets obnoxious, I pick him up and pet him, and he calms right down, but the behavior returns later. It's a good thing I'm a masochist, because I don't really mind his pecking. However, he attacked a visitor the other night. Lucky for him, it was a very nice woman. Had it been a mean man, he might have gotten his neck wrung, but it was a wake-up call, and I will always keep him penned up from now on.
Oh, and also, the good news is they get over this nasty behavior, usually, once the teenage time is over, which is when they turn a year old. My boy is almost 8 months old and in the prime of his bad behavior.
So one of these days we'll look back wistfully to these days when our roosters were so lively and testosterone-charged. Time passes so quickly. Before long our roosters will be "old men" and we'll long for these days. Enjoy them while they last. We get to see roosters in action who are full of the zest for life. I think we are the lucky ones.
My boy is a crower, too. He crowed precociously at 7 12 weeks. I had to raise him indoors with me because when he hatched he was unruly and went in every direction under his first-time mother Stepmama hen who nearly pecked him to death. That is when I determined he was a boy-- the hens were very orderly and conformist, unlike my rooster chick.
He lived in my solarium and ate all my precious plants I was overwintering. I think the extra nutrition enhanced his brain and enabled him to crow super early, and his first crow was perfect, no practice needed, and he has crowed nonstop ever since. 20-30 crows in a row is about right. LOL. And loud, shrill crows. At least he didn't crow at the full moon the other night! I heard of some roosters doing that.
My boy has crowed as early as 5:30 a.m. recently and as late as maybe 6 p.m.
Good luck. Enjoy your boy while you can!