So big deal if you like metal. Everyone knows that they do it because it sells merchandise and even if some are satanic advertising it won't help them. Being connected to that stuff can be detrimental in a big way.
You should be happy that you like metal, and if they make fun of you they are just shallow and immature. Metal music is liked by alot of people, your mnot alone just remember that.
I think you are trying to make people think you're a freak. You can't identify your entire personality by the music you listen to. There is infinitely more to a person than that.
As far as being an Atheist, you're not old enough to decide something as important as that. You're a kid. People will avoid you because you promote yourself as 'different'.
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.