I want to ask, is it possible that night predators are in the area and making him act this way, due to being rattled by them?
I wouldn't let this ruin your love of raising animals.
In schools you see this where kids learn to hate school or resent authority. And after this happens its a completely different life for them. I think this is useful to compare to. Before people learn to resent and hate school, they are all sweet and nice and everything is wonderful. Then it becomes a nightmare after they hate it. Don't let this happen to your animal raising.
So based on this I would switch out the rooster to something else. With ducks there are always people giving up extra drakes. I see this in free classifieds (or for cheap). I wonder if that's the same thing for roosters?