Apocalypse Mechanic is a Manga/Manhwa/Manhua in (English/Raw) language, Manhua series, english chapters have been translated and you can read them here. You are reading Apocalypse Mechanic chapters on https://mangabtt.com, fastest updating comic site. The Summary is
The Apocalypse has broken out, and the zombie virus has spread wildly. Ye Bei was persecuted by the squad leader of the “White Lotus B*tch”, his arm was bitten off by a zombie, and he’s lived like a cockroach for fifty years in the apocalypse. With his own efforts to become a mechanic, Ye Bei developed a time machine, returned to the beginning of the end 50 years ago, and re-writ his legendary life. Having seen the sinister hearts of people, he vowed to be worse, more selfish, and more villainous than everyone else. The first thing he did after successfully crossing back was to push the female class representative out to feed the zombies!