Hi Kendall,
My boyfriend didn't vomit too much but I found that 5 of the nutrician drinks were too much for Martin, but he could manage 4. Also, if he sat up for 1/2 hour at least after the feed, he didn't feel nauseaous. Martin had some anti nausea tablets called Ondemet and they seemed to help. our hospital gave them as standard.
Maybe he also needs a kick to get him back on track. I hope you 2 can get through this and I do hope he listens to you and feels better soon.
C