phew. last night he asked for some pasta. his ped had said he could have some, plain, if it sounded good to him. I gave him a smallish helping...enough, but not too much, and he ate it all. slept thru the night, and this morning has eaten a little more, had something to drink, and (the best part) finally started playing again. he's not totally back to normal, but so much closer than he has been.
hopefully the trend will continue. I feel so much better about him.