Phoebe: I'm not surprised, but can't say it doesn't hurt because it does.
That’s really it. Even when we know it’s coming and expect it, it still hurts to be cut off and shunned by people we care for.
It sounds like the one sister that “left” for a time probably is still a believer. I say that because she returned and is now shunning you for leaving.
You might try and remind her of that, but remember her WT indoctrination will cause her to interpret your real, unconditional friendship as “spiritual weakness” on your part.
Sorry you’re dealing with this. It sucks to find out that we’ve invested time and emotion into people that can’t return the same unconditionally. But you have learned some important things about yourself and what kind of person you are.
Now you have the opportunity to make real friendships and find people that love you for WHO you are and not WHAT YOU (pretend to) BELIEVE.