Arg...

I need to get some of this out before I sleep...
Our household seems to be suffering from discipline displacement. My mom seems to want to take the easiest and fastest route to ending a dispute, be it logical and fair or not. Forget fighting with the unreasonable 13yo, let's get the 18yo, who is guaranteed to listen, to back down. Then the 13yo turns on her sweet-talk, and everything's great. So, what really happened: I was in bed. I had been in bed for about 5 minutes. Sasha was brushing her teeth, and was coming to bed soon. I shut off the lights in our bedroom. It was 11 o'clock, I was tired, she should have been in bed awhile ago, etc. She marches in and turns on a light 'so she could see'. She could have left the bedroom door open a bit; that would provide light for her, but in such a way that it didn't fall on my bed as much. But she chose to turn on a light that cast plenty of photons directly at me. I was mad. Duh. Who wouldn't be? Julie never did things like that when we were roommates. If she was up after me, she did her best to find a way to use a light in a way that it would bother me the least. Aka, she was considerate of the fact I wanted to sleep. Not so here. I told Sasha to turn off the light. Mom comes in and tells _me_ to grow up. Fine; I could have handled that better. But does Sasha get any reprimand? Nope. Heavens forbid I get upset at someone blatantly trying to disturb me, but she can go right ahead and disturb me, no problem. It's all my fault. I was on the verge of just telling Mom to leave me alone, forget tucking me in, but I knew I would feel even worse if I did. Meanwhile, Sasha is as loud as legitimately possible while saying goodnight to Mom and Dad.
I don't know what to do anymore. Every single day, something like this happens. Yesterday, it was Sasha stuffing a baseball down the hood of my sweater. I took it out, and held onto it. She started shuffling up to me, coming within a centimeter of me, saying things like "gimme the ball, gimme it back" in a very childish voice. I am very protective of my personal space. Both my sisters know that, unfortunately with the occasional bruise to prove it. Do Not Touch Me, Period. I hate it. I told Sasha to back off, with a few pushes to drive the point home. She continued to demand the ball, never once staying back, continuously trying to move closer. I continued to tell her to get away from me. This was all with Mom sitting right next to us. Sasha starts screaming and crying for her ball back, all the while still not getting out of my space! Now Mom intervenes, telling Sasha to get a grip, and asking for the ball herself, which I gladly give up. Then Nicky decides to pitch in, and tell Mom and I that we're the ones in the wrong. As if Sasha's some 5yo that can't behave herself unless she gets what she wants, exactly when she wants it. Mom goes back to whatever she had been doing before on her computer, leaving me to argue with Nicky. The only thing I think I could have done better was to rephrase myself, saying that if she backed away, she would get the ball back, which I guess I never stated. Fine. But does that mean Sasha gets to throw a hissy fit?
I'm stuck. I obviously can't be a parent, but without any clear rules as to what the rules are, I don't know what to do besides pick the course of action that seems to be the best to me at the time, and deal with the consequences. Mom is tired of fighting. I've been gone for the past 8 months, I didn't tire her out. I want to help! But I have not a damn clue as to how to do that!!! I would love to give her my energy to fit and discipline, but I can't. Dad isn't home for all that long every day. There are no bedtimes, very little school, Mom busy doing ten things at once. I am not going to be walked over by my sisters, the way they do to Mom. I guess that's why I'm the focal point of these fights all of a sudden. It's all an authority thing; everyone trying to exert it over everyone else, because the one who is supposed to be lawfully and morally exerting it doesn't want to. I hope I get that job in Sackville. I want out of this house. I want to go back to where people try to be civilized to each other.

There may be some exaggerations in the above post. I'm tired and upset. It's nearing midnight. Take it with a grain of salt.