My Goodness Joli!  I can't imagine being in your position, handicapped and being cared for by an N.  Do you think social services will be of much help?  Right about now I would be letting people know what is really going on.  Write you r other daughter and have the social worker mail it to her.  You really could be in a dangerous situation.  Keep a journal of what goes on and hide it somewhere good so she doesn't find it.  You have to be able to prove what is going on somehow.  Is there anyone at all that you can trust that can help you?