Hey Sammy90, welcome to the forums.
I'm very sorry to hear about you and your Sister, is she safe right now, and are you? As Sophie said, please call 000 and say you're having suicidal thoughts, as this would be an emergency if you're unsafe.
You're in a safe place here, but I hope you are both actually safe in person. As Summer Rose mentioned, you're being supportive of your Sister and I'm sure she appreciates that even if she's in hysterics.
Can she get anyone to help her right now - Emergency Services, a helpline, anything like that?
We're all here for you, and we hope you're both safe.