I only read the first paragraph, and scanned through the rest as it was tooo loonnggg.. .. but from what I read you should dumb your girlfriend you gave her to many chances You should definantly go out with the younger sister she seem nice and caring. You don't have to tell your girlfriend that your going out with her younger sister maybe keep it quiet for a bit and if you do see things are getting serious between you and your gf's sister then you can tell her...x.
Leave the younger sister out of this for now.. you need to ditch your current girlfriend first, she isn't even treating you right. Once things cool down, rethink the situation & decide if you want to get into a relationship with the younger sister or not.
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.