It is definitely too late to back out, but that's really beside the point. If things were really bad, your parents would find a way to get you out of there and into your local public school. But things really aren't that bad.
You have at least 4 friends there and will be rooming with your best friend. I'm sure your parents are sending there to give you a leg up on your future - doing well at this school will make it that much easier to get into a really good college, which will in turn lead to you having a much better education and a better career. You probably can't think that far ahead right now, but your parents are doing that for you by sending you there.
The fact that there are mean girls there - well, sorry to say this, but there are mean girls EVERYWHERE, including at whatever other school you think you'd rather go to. It's just a fact of life. You need to learn to ignore those girls and focus on the friends you have and making friends with people you don't even know yet.
You'll do fine - you just need to stop focusing on all the negative stuff and remember all the good things about being there. As for being separated from your parents, just make sure your mom and dad know what you said here - that you feel much closer to them after this summer and will really miss them. Maybe they can arrange more visits, Skype sessions, and care packages to make you feel less home sick.
Good luck!
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.