My 15 Y.o. Daughter Has Been In Bed For 7

My 15 y.o. daughter has been in bed for 7 weeks with extreme nausea with no reprieve & vomiting about 3 x / week. This onset started the same day she started Zypan (naturopathic, 2 tablets & then stopped) - probably just coincidental. It also started with dizziness for a week & then went away with 1/2 tablet of Diazepam.
Addt'l symptoms: head throbbing/pounding 1-2x/week, mild tension/pain in right scapular region, throat tightness when swallowing, tired constantly with intermittent exhaustion, intermittent bad taste in back of throat when eating, nausea worse at night/morning & after eating, intermittent feel of burining up never with fever & muscle aching/weakness, one 3 "nights only" bout of right bikini line intense pain (front & back).
We've had tons of blood tests, ultrasound of abdomen/pelvic, stomach xray, stomach emptying study, endoscopy - only thing abnormal was from scope (yellow bilious fluid & mild gastritis). She's now back on Lanzoprazole for acid suppression although it didn't help her symptoms when she was on it before for 3 weeks. Pediatric GI may order head scan, preventative med for post infectious gastroparesis, and/or Elavil for cyclical vomiting. I just want a cause (a diagnosable diagnosis, not a guess) so we are not shoving meds down her with no success. HIDA scan is next.
I'm willing to drive 5 hours from Spokane to Seattle (Children's Hospital ER) if I thought she could get admitted. Do you know the odds of getting her admitted via ER, since this is taking a long time to rule out all this on a first available type of schedule not being admitted? I also have a friend who had success with a biochemical geneticist with her son (keytone utilization disorder, enzyme testing) - but he needs a referral & our GI laughed at us & said that would be way, way, way down the road. I'd be so gracious for any help in where to go for more immediate help and/or possibilities of what's causing this?