Zombie survival tactics? 'The Remaining' series by D.J. Molles is the gold standard, hands down. The main character is a military guy, but the series meticulously breaks down gear, fortification, scavenging runs, and the psychology of long-term survival. It feels less like horror and more like a bleak field manual for the end of the world, which is exactly what makes it so compelling for that specific itch.
You finish each book feeling like you could maybe, possibly, last a week longer than everyone else.