Wow, you've had a really rough time!
Sorry, I don't know much about this, but I remember our pead telling us, when DS was very young and there were some issues (which turned out to be nothing) that sometimes babies couldnt' have dairy protein and that meant eliminating all dairy and pumping and dumping in the meantime till it was out of the mother's system. I think he said it took a couple of weeks...? So yes, based on my very limited knowledge I would say it may be possible to continue breastfeeding.
Maybe Barb, our resident LC, will see this and give you better answers.

All the best~~