I'm 24 and 5'5"
Most remedies for car sickness have proven to have little effect (pressure points, tums, ginger water tablets and products, being the driver, and bicarbonate of soda if I remember the name right). Dramamine is best at the price of drowsiness, but sometimes isn't strong enough to overcome the nausea. However, that was before this started, and I don't think I can risk experimenting with the car. For what it's worth, I was diagnosed with enlarged vestibules (not aquaducts thankfully), enlarged lateral semicircular canals, and vestibular dysplasia. I don't really know what that all means, but it's the only diagnosis I was given by my ENT and to my knowledge it doesn't have a conventional name either.

My GI doctor recommends tertiary care from here, although my local university decided scheduling me 6 months out was a reasonable thing to, and did not adhere to his nor my requests of such care, so I've asked him to instead recommend me to Mayo Clinic for tertiary care instead, though traveling that far will be so difficult for me, I'd have to know I could stay long-term. Hopefully if I get a call, I can ask a Mayo GI about a duplex ultrasound.
The gastric emptying test didn't hurt any more than eating usually causes me. Colonoscopy prep was a nightmare for me though. It wasn't physically painful outside of when I was throwing up the solution at least.