Double Apocalypse: I Have the Strongest Fortress

I have lived through the apocalypse twice. The first time, zombies were rampant, and I struggled in a flesh-and-blood purgatory for three years. The second time the Ice Age came, I watched my last companion turn into an ice sculpture in the cold wave of minus 70 degrees. Then, I was born again. Back to the tenth day before the zombie outbreak. This time, I knew all the tragic scripts. I know the secret door of the supermarket warehouse, I know the password to the bank vault, I know who will turn into a monster on the first day, and I even know... Five years later, the deadly extreme cold will devour everything, and the zombies will evolve into more terrifying forms in the ice and snow. Time is only ten days. I bet all my memory, mortgage everything, call on all resources, and have only one goal: Before the end comes, build an ultimate fortress that can withstand double catastrophes. When the zombies come in like waves, my fortress is silent, and the steel gate slowly closes. When the ice age froze the planet, my fortress was as warm as spring, and the ecological cycle system ran stably. When the evolved "frost skeletons" hunted in the snowstorm, my sentry turret automatically locked onto their blue eyes. They said I was cold-blooded, paranoid, and guarding an isolated island. They don't know that I have seen the deepest darkness of human nature and the last glimmer of civilization. This time, I didn't just have to survive. I will still be on the ruins of this double apocalypse... For mankind, keep the last fire and dawn.