I'm truly sorry you are going through a hard time right now. If staying with your sister is an option, even just long enough to figure out what you want your next step is, I would suggest you do. You deserve better than this and don't deserve to be treated this way in any situation let alone during a trying time. This can give you a safe space to grieve and it may help you refrain for cutting. I recently relapsed and I know that it feels like it's the only thing that helps, but its not. Stay strong, you got this!