Malty, I hope things get better. They will someday, even if not much. Honestly, it couldn't get too much worse. I agree, you're in a terrible position. You aren't a super-girl, able to leap over mile-high problems in a single bound. None of us are. Hopefully, you can slowly climb them, little by little.
I won't say "I know how you feel," because I don't. I won't say, "You'll get over it soon," because you won't. I won't say "It's not a big deal," because it's a huge deal.
You might not be strong, but you're not weak enough to not get through this. If there's anything at all I can do, I'll do it. You might hate yourself, but I love you. please don't take that weirdly lol
If you need some sort of IRL support, try talking to your sister more, or any other siblings you have.
This is a huge thing, and a hard thing. Honestly, I couldn't deal with it half as well as you, and you aren't exactly singing for joy- nobody with a brain would be.
You're hanging onto the last rung of the ladder, but you haven't fallen off just yet.
In short, you're a beautiful human being that, with a lot of effort and definitely a lot of pain, can come out the other end of this experience alive, if not a better person from it.
I know this probably won't help at all, heh. I just really, really wanted to make sure you knew that you mean a lot to me, and I will do anything I can to help you.