There was something discussed here previously, possibly in the SN Megathread but not sure, about telling a doctor that at some point in the past, you have had severe nausea and vomiting and your were prescribed (by a different doctor) some type (take your pick) of anti-emetic, and that is the only relief that you have gotten when those conditions flared up. And you have tried all the OTC stuff and none of it has worked. If you can find the thread, it had other information on how to present yourself for that sort of thing. I'm pretty sure it didn't involve vomiting on your current doctor's shoes, but hey, if you could find a way to do that, I'm sure it wouldn't hurt. I'd do a search of "obtaining anti-emetics" or something like that.