I'm mad today

Today we've lost a chicken. She had problems with her reproductive system, an egg probably broke inside her and we had to let her go. The vet said there's nothing we could have done to prevent it and that it's part of the job description of being a hen. So far we have lost 3 hens due to issues with the Oviduct and all 3 of them were ugly and got bad very quickly. I try to protect them from outside danger and predators, I clean their shed and area every day, I give them minerals and supplements, I take them to the vet, I write down who's laying and how often so I can spot issues quickly and I try to do everything in my power to make them as happy and healthy as possible and when they get old they can retire and I'm happy when they get to stop laying eggs. But I can't protect them from their own bodies and how we made them lay so many eggs that it kills them...i know thats part of being a chicken owner and tomorrow I'll go back to doing my best but today I'm just mad.