Sounds to me that your mom obviously worries about you but has yet to realize that you're an adult and you're the one who's taking care of her. Maybe your mom feels that she's lost control of thinks in her life (ex. Dad never home, daughters taking care of her...,) so she just us trying to hold onto what little she has left of controlling.
And that's okay, But what's not okay is her becoming angry at you for not asking for permission to leave the house. I'd start with gently easing her into the transition of you coming and going whenever you please. Don't Ask her to leave the house, tell her you're leaving the house.
If she protests, explain to her exactly what you've said above. That should help at least a little bit.
You don't have to convince her of anything. You are 21 years old - move out!
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.