So I don't have a lot of time to type right now and the backstory is incredibly long, so I'll sum up:
We now know that Peanut is deathly allergic to peas, which with the first (and definitely last) attempt to feed it to him resulted in anaphylactic shock, a trip to the ER in an ambulance, his being transferred to Johns Hopkins Children's Center, and being admitted for two days for tests and observation. He now has to have an EpiPen Jr. near him at all times. All of the doctors said this also explains his six-week weight loss. We're grateful that his doctors are looking in this direction as previously his pediatrician believed I simply wasn't feeding him enough (the next prescribed step would have been to call Social Services to my home to monitor me and his environment to ensure I wasn't neglecting him since most weight loss in infants under six months (80%) is due to neglect or parental stupidity). So in a way the Peas Incident probably saved his life in the end.
His pediatric allergist specialsts said he's too young to tell conclusively everything he's allergic to as he hasn't had time to develop the antibodies in high enough numbers to show up on tests. Oh, and he is officially weaned as of three hours ago as the allergins in my breastmilk were making him sick and forcing the weight loss. So with his new and WAY too expensive hypoallergenic formula he should start to gain weight now (he now weighs less than he did 3-4 months ago).
Peanut will also need to have several appointments with a pediatric gastroenterologist. They are confident that most of his allergies manifest themselves in his GI tract (hence the weight loss) and it's very likely he has a few very rare diseases contributing to the problem, which they'll test for with an endoscopy and colonoscopy.
And a big round of applause for my sainted, patient mother who flew out on short notice Tuesday afternoon to force Peanut to take a bottle--something he'd become conditioned to believe would cause him pain because the milk-based formulas caused immediate painful reactions. She flew back home this afternoon after complete success with her. The real test came when I reintroduced myself to my poor son (I had been banished from seeing him for two days to make sure this worked) and had to give him a bottle myself. He hated the breastmilk and barely made it through that bottle (a transition tool I had thought would work). And yet when it came time for bed and I gave him the formula, which honestly tastes like the worst thing you've ever put in your mouth, ever, he drank it like crazy. So no more nursing for me! Woohoo for both of us! May our lives become instantly better as a result. Can I just say that this is the first time I've ever laid Peanut down in his crib while he was wide awake and he didn't scream when I left? He just rolled over and went to sleep on his own. Seven months of screaming his poor little head off and we never knew why. Now he's finally happy. I just hope he starts to gain weight again soon. He's so skinny (only 11 lbs now), it's depressing. His doctors assured us he has a long way to go before he is permanently damaged or anything, but I'd like to not push it.
So that's why I haven't posted in a while. Many thanks to those whose prayers and good thoughts got him through this. More prayers would be more than welcome.