First, we're so sorry to hear about the loss of your chicken. Losing any pet is hard, but there's something about having a bird who begs for pets and wants to snuggle on your lap that's just a little magical---the loss can feel completely devastating. And there's no magic bullet, either. Nothing we can say can make the loss of a pet hurt any less.
Pet chickens are as much members of the family as other pets are.
We empathize. We all keep chickens, so we have all lost chickens before, too. Recently, one employee lost every chicken but one when an automatic door failed to close. Another employee has lost a whole flock to a fire. Others have lost chickens to predators, injury. To a cold snap. Even old age.
Here's the hard truth that we know all too well: you'll probably experience more losses with chickens than with other pets.
While chickens CAN live to be a couple decades old, that's really fairly unusual. It's more common for the chicken lifespan to be 8 to 10, shorter than cats' or dogs' lives. Plus, chickens are prey animals, so it's common to lose a chicken to a predator like a hawk or a dog, even in town. Additionally, since chickens are flock animals, you'll have (comparatively) a lot of animals. Even with a small flock, you have 10 or 20 pets rather than one or two dogs/cats.
When you keep chickens, you're going to lose chickens. And it's terribly painful in a way that people who don't keep chickens can't quite understand.
But just because losses are inevitable, that doesn't mean you shouldn't mourn. Believe us: it's hurts. Because even though chick losses due to shipping are low, when you're the one person out of 100 who has chicks die in shipping it just doesn't feel that way. You can lose chickens to predators even when you've been sure for years your set-up is predator proof. You can do everything right with your biosecurity and sanitation, and have an illness creep in on you, passed from wild birds or brought in on your shoes when you stopped at the feed store.
Telling someone to toughen up about losses is just not something that most of us can do on command, you know?
"Oh, don't be sad, you say? Hmm, what a great idea, I think I'll stop being sad now!" Not.
But that said, it can help to try to have a farmer mindset about it. With chickens you're just a little closer to the circle of life, moreso than with keeping a dog or cat. That circle includes hatches---and also deaths. Some losses are just out of your hands: if the power goes out overnight and your baby chicks don't have access to heat, there's nothing you reasonably could have done, not unless you're prepared to get your brooder off-grid.
Instead, after losses, if there are changes or improvements you can make to your setup, focus your energy on those.
Bottom line, try to go into chickens mentally prepared for losses. When they happen, mourn. Then address anything addressable, and move on the wiser. No matter how long you keep chickens, you'll always have losses, we're sorry to say. Some people say losses get easier and easier, but we don't really find that to be the case. They don't really get easier. You just learn to carry the pain better.