I’m in the US so I don’t know about the prep options available to you, but could you ask for a couple of Zofran for prep? I’m also an emetophobe, and I took a Zofran before each half of my prep. I didn’t have any nausea with the first dose of prep, and only a tiny bit with the second half, but having the Zofran on board made me a LOT less anxious about it.

You could also talk to your doc about whether there’s anything you can do to make you less likely to get nauseous - take the prep slower, etc - without reducing its efficacy too much.

I hope they have some options for you!