My father in law used to be awful about this. It has improved greatly because I don't like that game. It annoys me. I have lots of relatives who play it and they all think that family means I am there for them but they are totally not required to ever do anything to help me or be nice to me. Many of them won't even acknowledge me unless they want/need something from me. Walk past me in public with-o saying Hi type not acknowledging me, literally. (Is it awful that I can have great fun insisting they notice me in these situations, esp if they are with other people?)
I am sorry this is such a challenge and source of pain and stress for you right now. All you can do is respect yourself and insist that others do the same. Not being able to control others is probably the hardest part about being a grown up.
(((((hugs)))))