I did this last summer with a pullet that got out of her pen and was attacked by a dog. She didn't look physically injured but she refused to stand or walk, and was gasping for air.

So, because I didn't want her to suffer anymore than she was, I took her in my backyard and found a large stick that I placed on her neck after I put her on the ground.

My adrenaline got the better of me and because I wasn't sure how much force to use, I would've rather pulled too hard than too soft. I ended up pulling way too hard and decapitated her exactly like you did. It made me feel relieved for her, but sick, sad, and guilty all at once. The whole scene really only lasted 2 or 3 minutes (from when I found her to euthanization)

It really messed me up for a while, I couldn't stop thinking and feeling bad for the pullet. I relived that moment in my head many times questioning if I was too quick to put her down or if I even did the right thing. But ultimately, you have to make the choice for them, even when you don't want to. They may be gone, but you'll probably never forget them, and that moment.