Parents favoring twin sister?

for whatever reason, they have chosen her over you, i know what this feels like as my mother thinks the sun rises and sets on her alcoholic parasitic son but her daughters don't even get a simple thank you for all the stuff they have done for her for years! Easiest solution? walk away and don't look back, doesn't matter what you do, it won't make a difference. living on your own somewhere can't be any worse than what you have, see a social worker, get things documented and carry on with your own life. stop trying to make the blind see,