it seems we must be sharing the same DD lol
have you taken her to your gp? maybe she has reflux... usually what you are describing can be a case for it, it also produces acids in the stomach which can actually be what those juices are that are coming up..
have you tried giving her a warm bath at night to ease her and relax her muscles?
i find with dd in which she has become extremely unsettles lately like today she cried for 3 hrs non stop nothing settled her and she was exhausted and all it was, was this harsh little burp and a little vomit not much just a tad and then she was fine..so i gave her a bath and feed and put her to sleep.
i would probably consult your GP and see what he/she says..
even though there maybe nothing wrong its still very distressing to hear them cry so painfully... and your right you cant leave her like that.. the more they cry the more hysterical and unsettled i say... itms??