Most Helpful Guy
If moving will make you happier, go for it. Yes, it's scary. It would give me pause and I'm a good deal older than you. But I'd do it, to get out of the situation you're in. Just curious, though, as to why your sister/mother don't get counseling and/or medication for these issues? There's a lot of free help out there.
Most Helpful Girl
Why do you need to move to another city? Why can't you just move out? Don't let other people drag you down.