I agree, don't feel bad, you may have just really scared him, all that holding and giving treats etc, hasn't been very effective for me with roosters, I think it's a normal reflex to kick em when they attack you - the rooster has just learned you are not a rooster, you are a human and humans can kick, hard! so he prob learned not to mess with you.
I kinda know how you feel though, so I'll share a story...I let mama hen out for the first jaunt out of the baby pen with her six week old chicks...I carried a long piece of wood to 'herd' them, so she wouldn't wind up in thick woods, sheparding them in the side yard with weeds and good bugs...so the reject rooster comes running over and tries to hop on the hen - no courtship, she's fluffed up and warning to stay away, but no, idiot boy won't back off, (I was worried about the chicks getting hurt too) So I whacked him on the neck really hard, hard enough to break the stick (okay it was kinda rotted in places) and the rooster falls on the ground flopping around - wow - I thought I broke his neck, or maybe hit him in the head and he's having a seizure or something, then I realize he's humping the ground:/
I couldn't see all the chicks and thought one might be caught under him, so I kicked him ...like a football...fortunately the chicks were all in the tall grass...that day he became slated for thanksgiving (since there's no turkey season in fall here)
He was fine, ran off but kept looking back, dodging the rocks I threw at him...
So for the next week or 2 when I let the hen and kids out I have a pocket full of rocks and got pretty good at winging them where he was going be....the other day, I saw him hanging around too close, and was about to modify him when I noticed he was actually trying to offer the hen treats and keeping his distance, and actually behaving like a gentleman...I guess some just have to learn the hard way.
we'll prob still eat him though.