I also get really sick when I"m stressed and I can't keep many things down. The trap I fall into is I feel as if I can only eat bland carbs, and then I"m hungry all the time, so I overeat. I"ve found scrambled eggs work well, and soft cooked meats (like ropa viejo, etc.) can work, and then maybe some fruits...
If the stress will be ongoing, I really advise finding foods you can keep down and calorie counting... succeeding at that one things will help you feel less outta-control all over.
If you can't even keep water down, please see a doctor!
Hang in there!