The only way to avoid the sadness is to not have any at all. I know how you feel. We all do. I know we can't take your pain away, but we can offer all our shoulders. Don't get disheartened, which is easy to say. I've been into this 6 years and would never have changed my mind even now. I just would have never brought home Typhoid Mary.
Chickens will toughen you up and make you realize that (okay, me) life is far different than I thought it was and I never would have expected ending up with the mental strength to deal with reality. Every one of mine gets the best I know how, and is helped to heaven if they need to. I can't do any more than the best I can, and I have no control over nature, but I can make the earth time wonderful no matter how short life can be. (okay yes I've had a few glasses of wine shared with my chickens) And I can cry as long as I have to.