Welcome to BYC, where people understand that your flock wasn't "just chickens"; they meant something to you!
It is devastating when a predator wipes out your flock. I had one survivor when a mink attacked one of my coops. I beat myself up for not getting outside faster, for not having a more secure coop. I thought about throwing in the towel completely.
It's been more than a year, and I have much safer coops and runs now, but I will never completely feel it's safe for my babies. Better latches, more hardware cloth and several Nite Gard solar flashing lights haven been installed.
However, yesterday, in the middle of the day, I noticed my Buff Orp and Faverolles making a fuss in their coop. The door was open to let in some (rare) sunshine, and in the bottom of the coop was a possum. It was as determined to stay as I was to remove it.
After trying a shovel, a pipe wrench an a prybar to get it out from under a nest box, I used the good old southern Iowa method: With heavy gloved hands, I grabbed it by the tail and pulled it out. I can't bring myself to kill an animal that is grinning at me, so I boxed him up and relocated him off the property.
However, had it been a mink, I would have beaten it to death without regret.
Wishing you the best of luck when you rebuild your flock!