Hi Gneiss! That sucks!
The only thing I can say is to establish boundaries. For a long time I tried to cope with the things my family did to hurt me (unintentionally) by doing more for them, and sacrificing more of my life for them, and then drinking to help forget the mess I was making of my life. One day I realized I had no more left to give. That was the beginning of the end. My relationship with them is very different today and we are not as close...but it came to deciding to protect me or them and I choose myself. I still get sucked in at times, but I can recognize it now and pull back before it gets too bad.
My suggestion would be trying to find a way to pull back some from your family so that their double standards don't hurt you.
