Reborn to Discover This Isn't an Era Novel but a Calamity Novel

I was unexpectedly reborn. I thought I could finally change my miserable life for good, with no more heartache or regrets. The past was like smoke, and everything would fade away on the wind. I steeled myself and looked forward to a new future. My fate was mine to shape, not Heaven’s. Whatever it took, I would make something of myself and live this new life to the fullest. But I soon discovered that everything had changed. A catastrophe had struck, and I couldn’t tell whether it was a punishment for humanity or a catalyst for human evolution.