The meaning of the image is good, how it was executed I'm wary with, and the fact I've seen better work come out of you,
If you are going for the time wins over the worst nightmares, I would use imagery of time, such as clocks etc, then maybe use the Grim Reaper as a tool, not only for the imagery of time, but to emphasise the nightmare, also draw attention that time is a nightmare most fear giving the image a double meaning, and then you can bring the whole Nazi thing in as well, and well, to show time progresses, the poppy would be a fitting thing to add.
Hopefully I didn't take over too much, buts thats the sort of thing I would do to get that idea across artistically, however the Grim Reaper is a pain to model, as use an image if you must, if you adopt that idea