When I first read this post, I was horrified and really started to question the method, as I have also chosen SN. Now that we collectively have some more details, I am starting to put together what happened here... somewhat.
As far as what antiemetics OP took and what dosage or regimen was followed, she hasn't clarified.
She says she fasted for 12 hrs but was that 12hrs before she took the first sip at 9am? Also, she says she finished half the 30g glass (approx 15g) at around 10am... so what happened in the time space between that glass and the one she ended up taking later at night, technically the next morning at 4am?
IntelligentLeg, I apologize if I am misunderstanding the time frame here. I hope you begin to feel better and I am sorry you suffered through this attempt. I also hope you do not feel berated by questions here. Since this is such a popular method, many are concerned. However, it sounds like due to sipping the first cup (about 15g) you were able to keep the mixture down... did you then pass out after taking the first glass? Then wake up at 4am the next day essentially and try to take the 20g glass, which then caused you to vomit, etc? It could be because of the spacing out of dosages, and because you puked most of the second glass up, that there was simply not enough SN ingested at one time to be fatal for you. Again, I am so sorry you were in such pain and experienced these nightmarish symptoms.