I recommend " Survival on the Wasteland: I Have a Dyson Sphere ". This book was about a parallel world in the future. The third nuclear war broke out, and modern civilization was destroyed. The surviving humans struggled to survive on this wasteland. At the same time, mutated creatures, high radiation, high temperature areas, and cold areas seriously affected the survival of humans. The protagonist, Lin Yu, transmigrated and started his own business from an abandoned shelter. The setting of the destruction of modern civilization and the survival of the wasteland in this book matched the background information given in the question. I hope you like my recommendation.