I almost forgot about that aspect diaper rash urghh. Exspecially if it is viral and oh so painful for baby and mommy. (what ever you do do not use vasoline on it).
My oldest boy had to drink predigested milk. Allimentum I believe it was called. Smells terrible like the bottom of a trash can sitting for a month in 100 degree weather. But what about soy based milk products? Also are you sure it is not transitional from breast milk to milk instead of a intolerance?
My hat goes off to you poor girl. Though yes later you will see you are at the best years of mommy hood there are. I know right now it does not look so great from were you are sitting.