I am sorry about Cocky. It's easy to play the blame game, but it won't fill up the empty space that Cocky left. I have cried plenty of tears over chickens, so I know your pain is real.
Take care of your hens; they will need you more than ever now. He was likely trying to defend his flock when...
I am so sorry for your loss. Don't apologize for having a meltdown; I've done the same thing myself. I've had most, if not all, of the same reactions that you are having.
When a mink got into my first coop and killed three of my four original hens, I was ready to rehome the last one and never...