The computer and iphone and games are very addictive. They're designed that way. So take them away from her.
Lock them up. Tell her that she can get them each day after her homework is done, her violin is practiced, and her room is made up. You can also have computer setttings on your computer that will shut it off after an hour of use.
Get a lock for your bedroom closet, put her things in there, and lock them up. And maybe enroll her in a day program so that she is doing something while you're working. Tell her all this gently, that you want to help her learn good habits, and that this will help her with her future.
And then stop having this same argument over and over. It's destructive and it doesn't help.
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.