I am trying to make the break. I am a bit closer. IT has to be for you, not because you feel so bad for them. My mom was an RXA, she had 4 kids, 3 were addicts. I am am not, but believe me we all lost something living with a functional addict.
My RAA is a sibling who is old and frail, so I say the same things you are saying cause like Zoso says it is hard to make that choice. Not there yet but my guilt is dropping away slowly, because I need my life back. I worked hard and I deserve it.... so do you.
Hope this helps.... It sucks, but has staying made anything better?