OK, I know that you're summarizing, and you're encapsulating a lot - I agree that sacrifice can lead to spiritual development, and good things. But I have a question - maybe rhetorical, maybe not.
Why does it seem that "Christian" philosophy so often seems to lead to the oppression of women as autonomous, fully realized human beings, with a right to a life of their own that is not subsumed by others' needs?
I have a hard time believing that your therapist truly believes that sacrifice will aid in your emotional healing, emotional growth, religious insight, etc., when it's pushing you into sacrificing your life for a parent with mental illness issues, and a lifetime of poor decisions.
I would be very direct - "It seems that you are inclined for me to place my desires, ambitions, and life on hold to take care of a mother who has deep issues that I cannot solve - and in fact, taking them on in any real way will be detrimental to my hard-fought boundaries and healthy separation from mom's mental illness. Why does it feel that you are pushing me in that direction? What is your guidance for me if I simply say "No thanks, that doesn't work for me?"
If she didn't have a reasonable answer, I'd be looking for another therapist.
(If I am way off base here, I apologize; but my younger, falling into far-right Catholicism brother just spent time on FB schooling our sister on why losing Roe and bodily autonomy is just the same thing as being told a vaccine was mandated; I am sick to death of the structures and strictures that reinforce women's dreams, goals and lives as sacrificial in every instance).