Sad to hear as well and like so many others here, I've been there. Someone said that the only thing wrong with dogs is that they do not live as long as us. When you bring home that cute puppy, you are signing up for that sad day in the future when his life is over. Unless you are 80 years old when the puppy is born, the sad day is coming.
Still, it's so worth it. Dogs are so wonderful and it give us a chance to care for another being and give it a good life. I know that you are sad but you did well.