It took me an awfully long time to realize:
a) I couldn't nurse all the babies for them,
b) I wasn't the one looking for a way out,
c) when mom is told to stop BF to reduce bili level, the flip side is that
her milk must be what is "poisoning" her baby, so she quits.  (And 15 isn't
any big deal.)  I usually find that nothing I say or give her to read can
undo this tidbit of implied "fault" from her HCP.

And yes I feel terrible when a mom stops BF.  I KNOW what she and her baby
will miss.  It was my fourth baby before I nursed "successfully" and I still
have regrets about my babies who didn't get all the good stuff-physically
and emotionally (in spite of the fact they turned out OK).

But we aren't responsible for the bottle feeding culture and we can only
work on the cure one mom at a time. I know BF was easier for my daughters,
daughter-in-law, sister, nieces  (that's 8 moms and 20 babies!) And all the
moms who have wandered through my LLL life and so on.  They all add up and
maybe their daughters will have it easier.  People come up to me years later
and tell me what an impact I had on their BF life and how much they
appreciate it.  Sometimes though we'll never know what an impact we had,
good or bad.

Grieve a little, it sounds like you did what you could, and then move on to
the next mom that needs and will benefit from your special knowledge and
support.
And try not to let the turkeys get you down.