Goddamnit anon why must life be so difficult
I don't know what to tell you. The only thing I can is that she and her own family situation needs help. Daddy needs help or she needs to get away from him.
As for you, only postponing and not completely removing the idea of getting the fuck out Minnesota (with maybe your sister too), get out more and find some friends and others that can help YOU, do what you like to do. It may be hard given your time/energy restraints, but something needs to change if you or your sister are to break out of your current life routines. I don't know the answer, but I know there is an answer, even if it's not an easy one, that can help you move your lives forward.
As for the issues with lovers, either refine how you look for them or simply stop looking and focus on more important things (which you do have, in my opinion).