Robin, Yes, there is a lot going on here.  Thrush keeps coming to my mind.
Clicking can be a reaction to an itchy, irritated tongue and throat. Also
fussiness and gas can be caused by the yeast overgrowth. Then there is the
nipple pain and breast pain between feeds and vaginal itching, along with
plugged ducts and infection and baby's red bottom.  Is baby being treated
for yeast also?  Since the baby is gaining well, I would pursue the yeast
path.  As you know, getting the yeast back in proper balance can be a
challenge, but it CAN be done. Both baby and mother must be treated.  I hope
she has doctors who will ride this thing out with her. She will need a lot
of encouragement.

There is a lot in Lactnet Archives on yeast, which is a clue to how
difficult it is to deal with.

Pat Gima, IBCLC
Milwaukee