There are some rough spots to iron out. When the character says she couldn't sleep and then describes that she had, in fact, slept, you contradict yourself. Upon arrival at FBI headquarters, you used the adjective big.
Try to avoid using overly broad descriptions. Actually, I would probably change that part to something like, "As I entered the headquarters building, the gravity of the situation slammed into me like a ton of bricks covered in lead with some bowling balls thrown in on the side." The writing style you're using is called epistolary.
One of the most famous examples of this is Bram Stoker's Dracula. The problem you're going to run into, and could play with a bit, is how much a person can reasonable remember about their day? How credible is your writer, has she forgotten something?
Does she remember something with a tainted perspective? It seems to me like a person will not be able to remember most dialogue, just certain phrases and the broader meaning of it. Well, there you go, I hope you find this information helpful =) I encourage you to take a look at a few chapters of Dracula to see how it's structured and how the narrative flows through the documents.
A nice title could be The End. It'd make people who are at the bookstore look on the shelves and think The end of what? Ya know whatta I mean.
P. S If I didn't make it obvious it's the end of the world.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.