Alicia, I have seen cases where moms perservered with pumping and several
months later a non-nursing infant suddenly recovered enough from some
original problem (birth injury, lact of neurologic maturity, incoordination,
 oral aversion?) and went to breast. I doubt the deep breast pain is thrush
in the absence of other symptoms.  It probably is the obvious -- position and
latch-on (you mention her back hurts.  She is probably holding some awkward
position, afraid to move lest he shake loose.)  Help her find a comfortable
way to sit and put pillows under her arms as they support the baby.  Another
though.  Baby is feeding very often.  I suspect milk supply is diminished.
 You don't say how often she's been pumping, but that tends to drop off over
time, and with no baby at breast for so long, supply very likely is low.  If
flow rate is slow and milk scarce, baby is probably sucking very hard,
maintaining a lot of sustained negative pressure on the nipple.  This is
traumatic, and certainly can cause lots of radiating pain.  Withdrawing most
 supplements so abruptly may be too much. This might be a good time to try
feeding tube device again.  I would also advise some weight checks to make
sure baby is getting enough to eat.  This mom is very conscientious. She may
feel guilty if the baby drops weight and blame her own "selfish" desire to
breastfeed.  Just remind her slow and steady wins the race.  Thanks to her
determination and willingness to keep her options open, this lactation may
still be saved.  She doesn't have to suddenly make everything happen immed.
 The feeding tube during or cup feeds after will take some pressure off her
breasts in terms of the almost non-stop feeding.  The augmented milk flow of
a feeding tube device will hopefully reduce infant's over-sustained sucking.
If baby balks at the tube, perhaps a short course of Reglan to kick the
supply upstairs.  Lots of skin-to-skin and a renewed, sheltered nesting
period would be great for both of them.
Barbara Wilson-clay, BSE, IBCLC
priv. pract. Austin, Tx