I have never heard of domperidone, so I can't comment on it's effectiveness, but I'm quite surprised ondansetron isn't helping you. They use it to help chemo patients with their nausea. I've also always found it very effective, especially since it comes in those instant dissolving little wafers.
If you have access to phenergan(promethazine) I'd try that. It's definitely my go to antinausea drug.
If you're unable to keep anything down long enough to have a med start to work, you should probably go to the doctor's office or urgent care clinic. You could get a shot of promethazine and one of benadryl(diphenhydramine) and I bet you'd feel a lot better.
If lope is working for you you should take it. As long as you don't take massive doses for months on end you'll be fine. If you just use small amounts to get you through the day I don't think ack you're withdrawal time.
Now most people have already suggested most of these but I'll go ahead and say them anyways:
Phenergan(promethazine) - rx only shot or pill in US
Antihistamines, ie benadryl(diphenhydramine) - otc pill in US with shots being administered at offices
Dramamine - otc pill in the US
Weed
Ginger - ginger snap cookies, ginger ale, crystalized ginger (sold with the spices), etc