Amazing, suspenseful story. Once I started reading, I couldn't stop. Loved the flawed character of the narrator and the way this was as much a character driven short story as a thriller. You gave just the right level of detail about the apocalypse, letting the reader's imagination do the work. The random introspection on the mundane in the midst of peril was a perfect balance. This paragraph, for example:
"That was the party where he told me he was gay and attempted a kiss, I smiled at the memory. We blamed the drink for his advances and bad timing for my rejection of them. I'd just started getting serious with Dan. It's strange how things work out all because of timing, a few weeks earlier I might have said yes to him, a few weeks later I might have been single again, now he's gone and I'm with Dan forever, like things aren't scary enough. I mean really how can you ever split up with someone during an apocalypse? It really is til death do you part now."
I recently finished "McSweeney's Mammoth Treasury of Thrilling Tales" which is a collection of adventure short stories from noted authors. Frankly this was better than most of what was in that collection. I'd recommend a second eye on your writing for grammatical corrections but that's about it. A big Like from me!