My father is the same as this. Always trying to convince everyone how compassionate he is, and always saying he loves me unconditionally but then behaving in ways that don't convey that or add up to his words. They are actors. I am not an object and you are not an object to possess.
It is all about their own issues, and I've had to do the same thing...start telling him that no, I don't want to talk to or see him, that he isn't just entitled to my time and to see me whenever he wants...I actually have a say in the matter as well. He's getting the message now, although he is still trying to use my other family members to rope me back in.
I wasn't thinking too clearly yesterday to reply to my brother, but I have now opened the door to him contacting me again, but I intend to say that if he is acting on my father's behalf, then forget about it, I'm not interested, until he genuinely takes himself off to a therapist and commits to dealing with his issues...which he never will.
Taking back control in these small ways will help to establish your sense of being an autonomous, powerful person. And indeed, she isn't thinking about you at all, your sister is all about getting her needs met at any cost, and your needs simply aren't important to her. She is attached to what she can get from you...not you as a person. It's parasitic really.