I'm so PISSED!

Well, mainly it is due to my sis tht i'm pissed. For one, she's acting like a kid nowadays. Maybe its cz my dad's been pampering her and maybe there's something wrong with her brain. Well, I know that i shouldnt say all these things about my sis because it just plainly showed of how immature and of how much I'm jealous of her. But... seriously... I CANT STAND HER FOR WHATEVER REASONS!!!! ok. like just then. My dad's trying to keep in contact with his friend. well, to be exact, his brother-in-law. and so he's using my msn account as he doesnt have one and couldnt be bothered to open one.(well, he actually had one but is just that he's using mine). Anyways, we tried to make a video call to his friend and it failed for several attempts. We can see him but we can't hear him at all. And likewise, they(his family) cant hear us as well. So, we started to suspect that there's something wrong with th connection. so, in the end, i suggested them to use yahoo instead . And it worked!=)
lols...
We can see and hear them and they can see and hear us as well!! yay..
now come to the part where i wanted to talk about....
In my excitement in knowing that's working, I said that msn's crap cz the connection's poor. And so I started to chat with my cousin and thn my aunt joined in with a raised voice. So, tell me.
How can you concentrate when there are two parties talking? Surely, it is either him or her who had to stop talking so as to allow the other to speak. And guess what?!! my sis said something really loud through my ears and my aunt is trying to talk to me online. How am i going to respond to both people when they are both talking at the same thing about different things?
To make things worse, I had an ear infection and so my hearing was not that good. So, it is either me listening to my aunt or my sis. And since all that she's taking about are all in a blur. And i cant really hear her as my aunt's voice is really penetrating, so.. I asked my sis to be quiet cz my aunt's trying to say something and i CANT REALLY HEAR of what she's trying to say. What happened next was the thing which drove me really REALLY MAD!!! MY deary sister go and use the flies bat(is it what its called, you know, the thing used to hit the flies? ) to hit my head.
I WAS SO FRUSTRATED!!!!!!!and i just walked off from helping my dad . its pretty idiotic really and the irony of that was that she's my elder sister. I mean how can someone who's supposed to be elder than you acted that way?!! and she didnt even apologise. well, she did. but its only cuz my dad asked her to. I was deeply annoyed. Right now at this moment, I just wished that the disease she had (its called hidradenitis suppurativa) could not be cured here in aussie. and by that, she'll left with the option to fly home to malaysia as she needs to undergo an operation which would completely eradicate that disease of hers. The option's malaysia as it is cheaper to do it there. So, I'm keeping my hopes high. Call me a bad sister or someone who does not even know his/her moral values. I seriously could not stand someone who's behaving like the way she is now. I mean i know that i shouldnt think that way as what I've done was not liked by others and also they didnt really like of who i really am. But really, having to live under the same roof with someone who has not the intention to tolerate with others is totally unbearable!!