Don't you think endings should always be Sad?

Forget the ending and just start writing. As you write and form your story, as the plot thickens and the climax happens, you will find your ending. I wrote a story and didn't know how it would end, until after many pages I just stopped writing and realized I had reached the end and it was a good one.

Let your characters point the way.

I know how I want the readers to change and make things happen to my characters accordingly.

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.