I went through a period where I read every Apocalyptic book I could get my hands on, and kind of burned out. An oddball one is “Of Men and Monsters” by William Tenn (aka world-class skeptic Phillip Klass). Aliens invade and wipe most of us out. The ending is really, really creepy.
Have you tried any of the British-style “cozy catastrope” novels from the '50s and '60s? From Wyndham’s “Day of the Triffids” to John Christopher’s “No Blade of Grass” to Ward Moore’s “Greener than you Think”, to Jones’s “Denver is Missing” they all feature novel ways of wiping out the earth (Everyone is blinded in Triffids, grain won’t grow in Christopher’s, everything with chloriphyll grows too well and takes over in Moore’s and the atmosphere is poisoned from a mile above sea-level up in Jones’s book), they all feature small groups trying to survive. I think you’d enjoy them.
BTW: Spider Robinson, in “Telempath” has the most inventive way of destroying civilization I’ve ever read: Someone lets loose a virus that gives all humans the ability to dectect smells better than a bloodhound. And no ability to filter it or turn it off. Cities are destroyed in a matter of hours as people rush to get free of the scent.
Fenris