Reincarnating after the apocalypse

The apocalypse ended and mankind came out on top! Sadly, most of mankind would rather face the zombies again. Why? Because it wasn't the end! Rifts appeared in all major human cities. All of them with a countdown of seven days. Each day adding more unease and fear into humanity all the way until the last second where... nothing? I got reincarnated back two months before the apocalypse right as the countdown hit zero so I wouldn't know anyway. This is my first story so expect a couple of grammar mistakes here and there along with general issues that come along with inexperience. This is an zombie-apocalypse novel with a sprinkle of greek mythology. I do hope to produce the best novel I can so if you have some spare constructive feedback then please share it with me.