Out of sheert laziness I didn't read the whole quesyion. But if you cheated on him you should tell h im. Especially if you'll do it again, If you won't do it again and it was an accident then just let it go and never again do it.
But don't let this become a thing or you're just hurting him. Even if it was only once you should still tell him but in that case it's really up for you to decide if it's more important you get punished or not ruin a good thing.
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.