Punished With Survival

Is it truly possible? Can life be any worse than this? First it was my family, then my friends, then it was anyone and everyone, everywhere. It was my fault. When I was coming back from Mars, I thought my samples were harmless. I got too relaxed, and this disease got out. I wasn't careful enough, and carried this god-forsaken plague back with me. Yet I live. As though by some divine judgement, I am the only one on Earth immune. God damn it all! Why?! Why do I get to live while everyone else dies from my mistake?