You could separate your cockerel from the pullets for a while, and see if it helps.
Do they have lots of space? How many pullets? This doesn't sound good to me.
The best cockbirds are never too rough, even as idiot adolescents, IMO. If there's plenty of space for the pullets to escape, and they are being injured, he's being a jerk and that's very bad.
Often it's best to have a mixed age flock, so the youngsters learn polite behavior from their elders. This boy is apparently missing that, and it's too bad.
You can't 'make' him gentle!
I would never have a bird, especially a cockerel, anywhere near my face!!! He needs to respect humans; I hope this turns out better than it sounds right now.
Mary