I have a very similar issue, except I have never ever thrown up because of it. After a lot of careful tinkering I have figured out my "specifics" if you will, of the symptoms.
It does not matter what I eat before I go to bed, or if I even eat before I go to bed, and it does not matter what the time gap between bed time and last eating time was. It also does not matter if I drink water before bed, before meals, etc. I have had it as long as I can remember, which would be at least since I was around 8 or so.
Every single morning, when I wake up, if it is between the hours of 9 and 11:30'ish, I feel as if I ate something bad. I feel nauseated, however not in the "I have to throw up NOW" sense. It's more like... I feel as if I just ate something that was very bad (undercooked food) and my stomach feels like that would. Usually, I have a bowel movement, and it is almost always quite soft rather than hard (not liquid however like diarrhea would be). I feel OK after this, but still when I think of eating or even look at food I feel sick as if I couldn't eat another bite, even though I haven't had one yet.
Eventually, after about an hour or so of feeling like this, it suddenly goes away COMPLETELY, I feel 100% better and on top of that, I get incredibly hungry with the stomach growling and all. I can eat a full course meal and I even feel like doing so usually.
I was diagnosed with a small form of GERD and have stomach irritation because of it, I am currently taking NOVO-RANADINE pills twice daily, in order to help with other symptoms of GERD. It helps those fantastically with no issues, but as I said, I have always had this morning nausea feeling since I was a child at least.
Again, I have yet to throw up, and I do not upchuck either in my mouth. I don't have diarrhea usually although I do have a very odorous (upset smelling) and soft bowel movement. The other ones I may have throughout the day are normal, and they do not smell very odorous and are a lot more solid than the ones I take in the mornings.
I cannot figure out what it is, obviously it cannot be something too serious or it would have gotten worse in the years since I was a child. I am 25 years old now, 5"10 @ 179 pounds. I try to work out every day, however (which is a partial reason to posting this) this morning nausea really hinders it sometimes.. Try working out when you feel sick, not fun.
Usually I have to FORCE food down for that hour or so that it lasts (usually 9-11:30 as I stated above), if I can. I manage a bowl of oatmeal, but this is getting really ridiculous and annoying, waking up like this every single day no matter what steps you wake beforehand...