If you were turned on to zombies by the apocalyptic scenario, you might also be interested in
The War Against the Chtorr. For me this is more compelling as a doomsday scenario.
Earth is first truck by several plague waves that wipe out about 4/5 of the global populace. Then weird plants and animals are encountered, at least one of which is highly predatory toward humans. Although there is never any direct evidence, the military comes to the conclusion that the planet is in fact undergoing an alien invasion by the introduction of a foreign ecosystem, probably deliberately engineered. It's pretty bleak; mental disorders from various sorts of trauma are widespread, there are very few people with proper training in the fields in which they now work, and the situation seems to keep getting worse.
There's some dubious pyschology thrown in, and it's definite a love it or hate it type of thing, but given what you mention above it might be worth a look.