I have no doubt this is what your doctor said, but I think your doctor was confused. You didn't do anything wrong and your milk was fine. I don't have the whole story and can't say for sure, but it very much sounds like CMPA, since she did better on the soy. Soy is, of course, not a mammal milk and thus contains no cow's milk proteins. So a CMPA baby doesn't react to it (unless the baby is also allergic to soy). The only thing that makes sense is that he may have tested your milk to see if it contained cow's milk proteins, but a much easier way of doing that would to have been to have simply asked you if you ingest dairy. For the benefit of anyone else who may face this issue, the fix for that, if the mother wishes to continue nursing, is to cut dairy from her diet -- that means those proteins do not come through your milk anymore. This is another example of doctors who don't know how to manage lactation.

There isn't any judgment here for mothers. Just for our medical profession, which needs to do a much better job. Your story of a friend providing your daughter with donor milk for her baby is another example of women helping women. Mothers are usually very good about helping each other. We need the medical profession to do the same.