I was in the same position as you but I'm from the Netherlands. What I did:
Went to my local gp and said that I have undiagnosed migraines from a young age and that my mother used to give me domperidon to help against the nausea. I then mentioned that I went to my local farmacy and was suprised that domperidon wasn't available anymore without a prescription (before 2014 you could get it without prescription, this helped my case :).
Lastly, I requested if they could prescribe me with domperidon to combat the nausea during the migraines, which come up during stressful situations. The doc prescribed me with 4 pills, which ought to be enough for when the time comes.
Btw, I did the same thing to acquire oxazepam but with a different excuse and of course some time between.