Forget what Sophie said. Childline don't help for ****, trust me. I'd tell your mum; she'll understand.
She will not feel failed as a mum, since it's her duty to help you out in moments of despair. She'll feel like a better mum if she can help you out with this.
When I told my mom that I self harmed (I've been clean for about 3 years now) I wrote everything down on a piece of paper folded it up and sat it somewhere where I knew she would see it, and wrote "to mom" on the part she could see, and then I went to school and when I got home we talked about it. It gave her time to process everything and figure out how she wanted to approach it.
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.